Upper Radiator Hose --- Swells then Pops Off

[Evan]

My upper radiator hose swells and pops off.

This started happening after I replaced intake, pcv, water pump, and associated seals and gaskets.

Coolant temp stays fine but the upper hose just swells and pops off every time I think I have the system bled properly.

The heat works fine... the lower hose and lower radiator get hot.. there is no coolant in the oil.

What could be causing this buildup?

[Rus]

Check the cap on the coolant reservoir. If it isn't letting hot coolant escape into the reservoir, you could be building up way too much pressure in the system.

[Evan]

thanks... i've been checking and rechecking everything... especially the thin line to the expansion tank.

i'm mystified

[632 Regal]

get a new hose dude

[Boone.Msi]

get a new hose dude
+1

Hows your radiator looking, mine kept doing that due to the plastic connector chipping/breaking off.

[Evan]

the radiator is in good shape and water flows freely from top to bottom. i replaced the expansion tank hoses including the long plastic one that runs along the driver's side of the engine compartment.

the restriction causing this buildup seems to be in that area.. the area between the radiator and the expansion tank when i loosen the clamp on the tiny radiator outlet all the pressure is relieved.

jeff, i have new hoses but i don't think they'll help.. lend me your 850 for a month or two while i sort this out ;)

[MBXB]

Did you check the small hole in the expansion tank where the hose runs to?
Make sure it wasn't obstructed? Use a hobby hand drill to clear the opening up. Forgot what the bit size was.

[Evan]

I got around to checking this again today and this is what I found:

the hoses from the radiator to the expansion tank are unobstructed

when the expansion tank cap is on it doesn't allow pressure to escape.. I'm at my wit's end on this one... I feel as if I've isolated the problem but I may be on the completelyt wrong track!

[Dave M]

I got around to checking this again today and this is what I found:

the hoses from the radiator to the expansion tank are unobstructed

when the expansion tank cap is on it doesn't allow pressure to escape.. I'm at my wit's end on this one... I feel as if I've isolated the problem but I may be on the completelyt wrong track!

See Rus's post above. Time for a new cap??

[Evan]

I should have mentioned I just picked up the cap at the dealer...

so the lines are all unobstructed.. the cap is new... but pressure is building up...

i must have missed something?

[Dave M]

IF you have ruled out most 'obvious' cooling system related items, then, and only then, should you consider the big air pumps we call cylinders :(. What I'm getting at is the possibilty that exhaust gasses are breaching a head/headgasket, entering the cooling system and causing the issues. Now, I definitely don't want to cause a stir, but if you can't figure it out with general cooing system 'stuff, then begin with a compression test, leakdown test and/or one of those fancy exhaust gas tester thingies (I've never used one of the thingies). I had a very similar thing occur with my M50. No blown hoses, just a ton of residual pressure built up, which would still be there after a night of sitting. It ended up being a cracked head.

I should have started by asking whether you're 'using' any coolant or have any form of mixing going on in the crancase, cooling system. If you don't use a single drop or have any mixing, then its much less likely a head or gasket is shot.

Sorry if I put the fear in you. It seems as though you're at the end of your rope. Keep us posted,

Dave M

[Evan]

I checked for coolant in the oil and there I was relieved to NOT find any....

I'm checking the PCV system again

[Dave M]

I checked for coolant in the oil and there I was relieved to NOT find any....

I'm checking the PCV system again

You don't need to have coolant in the oil, it can enter the cylinder and burn. I assume you don't 'use' any coolant either? Not sure if you get exhaust gases breaching a head without the burning or mixing of anything.

Good luck finding a cheap solution. All the best,

Dave

[632 Regal]

M60's rarely have bad headgaskets, If I was you id chect the common things first such as thermostat, fan, aux fan and waterpump...dont forget the radiator for blockage either internal on on the surface of the front from dust dirt buildup.

[Evan]

thanks, Jeff

the t-stat and water pump are new and working properly.. the radiator is a year old and is working properly with no obstructions and good flow from top to bottom

the car is driveable and has full power so i dont think there is any issue other than some restriction in the cooling system

ive also don the fan/shroud delete mentioned by boone.msi (removed the fan and shroud and changed to a lower temp t-stat and lower temp thermo fan switch)

both setups have the same problem with pressure building up and not being released through the expansion tank...

[632 Regal]

Ahhh details details....



ive also don the fan/shroud delete mentioned by boone.msi (removed the fan and shroud and changed to a lower temp t-stat and lower temp thermo fan switch)

try putting the main componants back and see if you have a problem, the clutch fan and shroud do 90% of all cooling no matter where the temp guage is at. The thermostat is probably fully open and flowing so fast it isnt cooling the system but also returning cool water to the temp sensor. There was at a time a reason for the fan and shroud. The cold cylinders in front will wear at a rapid rate without a controll in place.

[Evan]

I'm already tested it stock and had the same problem but I'm going to do it again.

I haven't been driving the car until i get all the issues straightened out.

Thanks for the good advice!

[Alexlind123]

Thats what she said.

[Evan]

I'm baffled... same symptom with stock setup

[Tiger]

What happens when you reinstall your original cap?

Where on upper hose does it pops off? The radiator? The radiator is supposed to have a nub to prevent the clamp from sliding off... maybe your nubb is broken off...

[Evan]

I don't have the original cap.

The hose pops off because of the pressure building up in the upper hose.

I'm completely bamboozled at this point....

[Tiger]

Take upper hose off and see if you still have the ridge on the radiator that is supposed to prevent this from happening. I suspec the ridge is gone and your hose simply slides off under pressure.

[Evan]

the radiator is fine... everything is in great shape.

nothing will keep the hose on because the pressure is great...

[632 Regal]

I dissagree, if this is the case then all kinds of hoses would be popping off everywhere not just at 1 location.

Have you tried using a hose clamp on the thing?




nothing will keep the hose on because the pressure is great...

[Tiger]

I still think the nub is broken off and that all he has is smooth shaft.

[pingu]

I'm with Tiger and Regal on this one. Can you post a pic of the neck where the hose attaches to the radiator? And a pic of your hose clamp?

[Ross]

There are test kits available to detect exhaust gas in the coolant. Put a drop of something in a sample of coolant and see if it changes color sort of test.
If your pressure isn't accompanied by high temp then I'd start looking at a headgasket.

[Dave M]

Is there a way to check the system pressure via a screw on cap with a guage? Just thinking out loud.

Dave

[Ross]

Yep, rad. pressure gauge

[Dave M]

Yep, rad. pressure gauge
Sounds like the next thing I'd try.

[ThoreauHD]

I had the same issue on my E34. For some reason the radiator "nub" itself had a damaged lip and the hose kept popping off. Got a new radiator and hose, and then no problems. I don't know why it was damaged in the first place. Maybe it's a OE manufacturing defect from way back when. But if you say the radiator lip is there, and the hose is clamped on tight around said lip, then oh well. I don't know.

[Ferret]

Sounds like the next thing I'd try.

Try this:

Does this car have the top expansion tank?

If so, try the following:
Take rad cap off with car cold...
Get someone to peer indirectly into the expansion tank (so they dont get an eyeful of coolant)

Start the car and hold it at 4-5k rpm for about 30-60 seconds, while cold.
(This isnt good for your engine, but as a once off you'll be okay.)

If you've got a cracked head/busted head gasket, you'll see little bubbles start to rise in the expansion tank... they'll be carried all the way around the system by the coolant flow, and a couple should get carried away up to the expansion tank. (Be aware that there may be air still in the system from when you've blown the hose off and had to re-fill.)

Let the car return to idle and let it come up to temperature, IE hot coolant through both the top and bottom radiator hoses. If the hose doesnt pop off with the expansion cap still off, you've found your culprit. If the coolant boils, you'll have to re-bleed the whole system... but it shouldnt boil, it should be close to - but not go over the edge.

Anyone else concur with this method on this engine, this always used to work for me while I was working with the old 4-pot bl engines :)

[Vanguard]

you'll have to re-bleed the whole system

It's an M60, there's no provision for bleeding.

[Evan]

I'm going to work on her again after work.

The radiator neck and clamp are in fine condition. The upper hose swells like a balloon... it just isn't right.

My next step is to do a compression test and I'll post the numbers sometime today... in fact, screw work... my car is more important.

Something funky is going on and I'm going to find it this weekend! (That was me trying to sound confident even though I'm this close to breaking down and taking my car to the shop.)

[Vanguard]

Did you replace the upper hose during your testing? My experience is that while some swelling is normal, ballon like is not. If the hose is weak and deforming it may be affecting the clamp's ability to hold it on the radiator inlet. Enough streching of the hose is going to thin the material underneath the clamp thereby loosening it.

[Evan]

Here are the compression readings from my first test. I intend on doing another test tomorrow morning.

I removed the plug covers, coils, and plugs from the cold motor and got the following readings from my tester:

@180 @180

@165 @162

@165 @170

@170 @170

The above diagram represents the motor as if you were facing it from the front of the car with the first line of readings being the cylinders closest to the firewall and the left reading corresponding to the passenger's side of the car.

I'm not sure what they mean at this point but I think it could mean I have some valve leakage. I think the readings are indicative of a generally healthy motor.

Any opinions?

[Vanguard]

Looks pretty healthy to me. Everything is within 10% or so of and no single cylinder is unusually low.

[Dave M]

Here are the compression readings from my first test. I intend on doing another test tomorrow morning.

I removed the plug covers, coils, and plugs from the cold motor and got the following readings from my tester:

@180 @180

@165 @162

@165 @170

@170 @170

The above diagram represents the motor as if you were facing it from the front of the car with the first line of readings being the cylinders closest to the firewall and the left reading corresponding to the passenger's side of the car.

I'm not sure what they mean at this point but I think it could mean I have some valve leakage. I think the readings are indicative of a generally healthy motor.

Any opinions?

About the comp readings.

First, you did the test on a cold engine. Tests are 'supposed' to be done on a warm engine. You may want to try this the second time around.

Second, since you plan (I think) on doing a second test, for what its worth, attempt a 'wet' test by pouring a teaspoon of oil into each cylinder and repeating the test. Values should stay relatively stable in all cylinders without lower end issues (worn cylinders/rings). If you get a significant increase in the cylinders with low dry test values, it may be a sign of worn 'stuff down there' rather than valve or gasket issues. This is unrelated, but if I saw 162 next to a 180, It would interest me and I would want to narrow it down a bit if possible.

Aside from the comp test, you may want to step back a bit and try getting a coolant system pressure tester to see whether the pressure is off the charts (or simply find a place to give you the reading). The normal system pressure is available somewhere, someone here (Bill R or Winfred etc.) will know. Again, this would be my next step before reading into the results of your comp test too much. If the pressure is OK, back to the drawing board, if its sky high, then we'll have to have a talk ;)

Good luck, report back.

Dave

[Ross]

Doesn't look bad at all. Have you had a good look at the hose? Maybe it's just a **** hose and we are all chicken little here worried about the sky falling. Just a thought.
A pressure gauge on the cooling system will tell the tale.

[632 Regal]

looks good for a cold motor that sat for a while. Remember some of the hydraulic lifters will bleed some and affect compression readings.


Here are the compression readings from my first test. I intend on doing another test tomorrow morning.

I removed the plug covers, coils, and plugs from the cold motor and got the following readings from my tester:

@180 @180

@165 @162

@165 @170

@170 @170

The above diagram represents the motor as if you were facing it from the front of the car with the first line of readings being the cylinders closest to the firewall and the left reading corresponding to the passenger's side of the car.

I'm not sure what they mean at this point but I think it could mean I have some valve leakage. I think the readings are indicative of a generally healthy motor.

Any opinions?

[Evan]

I've decided to go ahead and remove the heads and have them checked for cracks and then replace the head gaskets.

I'll be doing a search for M60 head gasket threads and I'd love to hear some firsthand experiences from those of you who have them!

[whiskychaser]

[QUOTE=Evan]I've decided to go ahead and remove the heads and have them checked for cracks and then replace the head gaskets.

Did you check to see if any plugs are wet or if the coolant is black? Think I would want some definite answers before I started taking heads off :)

[Dave M]

Evan,

Did you ever get the cooling system pressure tested? Just wondering as I'm quite interested in this thread.

Dave

[Evan]

Dave, I didn't test the pressure but I suppose I can.

Just from looking I can tell you that the pressure is sky high... the hose is literally inflating like a balloon.. either compression or exhaust is getting into the cooling system.

My thinking is as follows:

Spend $200 at the BMW dealer to get a diagnosis that may or may not tell me whether I may or may not have a bad head gasket, cracked head, or some other problem...

Spend $400 on parts, tools, and beer... remove heads and have them checked for cracks, install new head gaskets, and do a valve job.

I'm thinking Warsteiner for the beer...

[AllGo'n'Show]

radiator ever replaced?

[Dave M]

Dave, I didn't test the pressure but I suppose I can.

Just from looking I can tell you that the pressure is sky high... the hose is literally inflating like a balloon.. either compression or exhaust is getting into the cooling system.

My thinking is as follows:

Spend $200 at the BMW dealer to get a diagnosis that may or may not tell me whether I may or may not have a bad head gasket, cracked head, or some other problem...

Spend $400 on parts, tools, and beer... remove heads and have them checked for cracks, install new head gaskets, and do a valve job.

I'm thinking Warsteiner for the beer...

I was thinking you could buy/rent/borrow the pressure tester and do it yourself. All you need to do is screw it on and get the car up to operating temp. Too bad you're having to go through this, but you will learn a heap.

Let us know what the gasket(s) head(s) look like.

Dave

[Dave M]

radiator ever replaced?


I think Evan went through all this. If he hasn't tested the rad, a first easy step would be to remove it, drain it, then run a hose through it or just blow through it while moving it around to see if an obstruction materializes.

[AllGo'n'Show]

whoops only read first page didnt see the other 4 lol, my bad.

[Evan]

I have another car to drive so it isn't as bad as it could be.

and... you're right.. I'm learning all kinds of **** I didn't think I'd be learning this summer ;)

[Evan]

The radiator is in good shape with no obstructions!

[Ferret]

The radiator is in good shape with no obstructions!

Did you not try running it without the radiator cap on?

This will imediately tell you whether it's a blockage or a leaking gasket...

EDIT: Whoops, on second thoughts I've just spotted that the system pressure purges happily if you remove the small bleeder line on the top of the rad.

You've deffo got a bad head gasket if it's doing this, as there's not much else that could cause this amount of pressure.

Unless, your new waterpump was duff from the get-go or you've got a coolant blockage in the engine block, thos're the only other things I think could cause it.

EDIT2 : Or a cracked head like the M50's are prone to doing.
Good luck!

[Evan]

I've narrowed it down to a head gasket or cracked head. I wish Winfred or Bill R. would read this thread... they know motors inside & out.


Also -- today I'm going to remove one of the block coolant drain plugs and see what happens... who knows.

Cheers,
Evan

[Dave M]

Also -- today I'm going to remove one of the block coolant drain plugs and see what happens... who knows.

Cheers,
Evan

I'll guess first. Blue shower.

:D

[Ferret]

I'll guess first. Blue shower.

:D


Hahaha lmao

[632 Regal]

dude this thread is crazy, I feel like deleting it due to nausium. as asked and suggested many times REPLACE THE RADIATOR HOSE FIRST, GOOD ONES DO NOT INFLATE LIKE BALLOONS, CAN YOU READ THIS? YOUR COMPRESSION READINGS ARE FINE. IF YOU STILL TAKE THE HEADS OFF WITHOUT REPLACING THE HOSE AND CHECKING PRESSURE YOU SHOULD BE LOCKED IN A CLOSET ALL SUMMER WITH NO BEER.

[Evan]

i'd ask what is "nausium" --but im too busy trying to figure out why my cooling system is pressurizing

[632 Regal]

thud thud thud
i'd ask what is "nausium" --but im too busy trying to figure out why my cooling system is pressurizing

[Tiger]

Just borrow a cooling system pressure tester from Autozone... hook it up to your system and if the pressure goes past 30 PSI, then you got a problem.

[Dave M]

nausium = three hours circling in a helicopter after a HEAVY night of drinking. Go ahead, ask me how I know :D

As for Jeff's COMMENT, I thought you had already changed hoses, so it was ruled out. Also, you comp results can be OK and still be leaking exhaust gases into the system.

However, he is correct if you haven't changed that hose. Probably shoudn't have cases of beer in a closet anyway, many problems associated with that.

Dave

[Evan]

he is not correct... hoses are new.

exhaust or compression is leaking into the cooling system.

i went to look for a pressure tester today (to humor jeff) but couldn't find a suitable one... any suggestions?

[AllGo'n'Show]

When you removed the plugs did you look to see if any of them were fouled with coolant/goo?

[Blitzkrieg Bob]

remove the radiator cap fill up to the top and run... see any bubbling?

[skr]

man, dem hoses don't inflate. they have some realy tough textile material in the rubber to keep them from doing that. my guess is that in can hold 10 bars without changing shape. and if you had 10 bars in the system you whould be blowing off all sorts of things. so, where did you buy your new hoses from and what is written on it? my advice is to get that pressure tested...then we will all stop sayin' **** about your hose. you can put a T on the expansion tank line, buy a pressure gauge (cheap) and connect it to the T. worth the money compared to removing heads. i'm just saying to try the cheap things first. and removing heads ain't one of the cheap ones.

[ryan roopnarine]

please squeeze the hose when hot, and tell us how far you can deflect it, and what force was required to do so. autozone's pressure tester doesn't have an adaptor to fit onto a bmw, buying one of those adaptors is like $40-50 by tiself.

[632 Regal]

Ohhh I didnt see that you replaced the hoses, yes remove the heads is next. My hoses only balloon when my head gaskets leak which is quite common on these engines...

he is not correct... hoses are new.

exhaust or compression is leaking into the cooling system.

i went to look for a pressure tester today (to humor jeff) but couldn't find a suitable one... any suggestions?

[Evan]

you can squeeze the hose maybe a millimeter at best... there is exhaust or compression leaking into the cooling system...

i didnt find a pressure tester today but i did find a nice orbital polisher and washed and waxed my baby... she aint goin far.. but she sure is lookin good

[Evan]

excellent point and yes i did... on the driver's side head there is one cylinder that had a fouled plug

[Evan]

The hose doesn't actually inflate... but it would if it could. It just swells and gets very hard...

It seems to be head gasket time! thank you all... im obliged

[632 Regal]

head gaskets seem to be pretty easy on an M60, someone just did them a month or so ago I read.
The hose doesn't actually inflate... but it would if it could. It just swells and gets very hard...

It seems to be head gasket time! thank you all... im obliged

[Evan]

im gonna start taking everything apart tomorrow... then take the heads to a machine shop on monday

im planning on having both heads tested & replacing both head gaskets

[Ross]

I think you're right on. The pressures you are describing without overheating could only come from the combustion gases seeping past a gasket or a crack.
Unless you have gotten real hot chances of cracks are slim.
Are any of the plugs really clean?

[Ferret]

im gonna start taking everything apart tomorrow... then take the heads to a machine shop on monday

im planning on having both heads tested & replacing both head gaskets

There's just one thing bugging me here... surely the expansion cap should blow before a hose does? You didnt put silicon hoses on did you or something daft like that?

[Evan]

no i didn't...

what am i doing is starting over and going over everything i did. i've put the car on ramps and removed the passenger side block coolant drain plug... i've removed and replaced the thermostat and hoses...

i've run the car with the hoses off to see which way the water circulates (the water pump pushes the coolant through the upper radiator hose and into the radiator.. i assume that's correct... i haven't been able to find a cooling system flow diagram)

i've run the hose through the radiator to check for obstruction (again)

so far everything seems normal... i'll reassemble and refill in a little while

if i can't get it fixed i'll have to go for a leakdown test, i suppose... but i'm learning a lot and having a little fun... so it's all good

[Ross]

Evan,
Pop those spark plugs out and have a look. A really clean one, in relation to the others, means coolant in the combustion chamber.
You've all the symptoms of a failed head gasket.

[Evan]

too late.. i poured gasoline all over her and she burned for a good seven hours