A sad day

[Paul in NZ]

for the first time in about seven years me and my 535 are more than a few metres apart.She is in the workshop with a suspected blown HG.Like the other poster i have no real signs of a blown HG,just a miss at start up and coolant loss,oli clean,coolant clean,no overheating,even after three days there is pressure in the cooling system,top hose firm to the squeeze immediately after shut down....:(

[Rus]

The top hose will be firm to the squeeze on a hot engine right after shut down. Don't see anything abnormal there. Good luck with the HG and hopefully it'll be just a replacement without any complications.

[Dave M]

The top hose will be firm to the squeeze on a hot engine right after shut down. Don't see anything abnormal there. Good luck with the HG and hopefully it'll be just a replacement without any complications.

It sounds a bit confusing, but he also said there is residual pressure after three days (???). Thats a looooong time to hold pressure.

Anyhow, I hope its an external leak.

Dave

[ryan roopnarine]

so sorry to hear that.

[Paul in NZ]

the shop rang me today...they arent sure but its looking likely.The aux pump is leaking so thats one source for the coolant loss but their is a build up of pressue while running enough to bulge the radiator!

[Ross]

The system holding pressure for three days and leaking from anywhere are contraindicative. Also if there is enough pressure to bulge the radiator the cap is defective, this pressure should be relieved.
There is a simple chemical test to determine if combustion gasses are present in the coolant. I suggest having this done.

[ryan roopnarine]

i went about 100k miles on a bowed out radiator, i suspect that it got that way when my car blew a headgasket. i didn't know it was bowed out until it came out of the car and I saw that a good number of the crimps were on the verge of being straightened back out. i say that you should tell them you want to keep it as a spare when they replace it.

ps..i'm not saying to drive around with the thing gushing water if that is the case, but from the situation as I garner it from this board, people in NZ/aus pay a premium for parts. i was losing about 500ml of water per 6 months in my car, and i was driving it about 700-1000 miles a week at the time. the leak wasn't occuring from the radiator.

[Jeff N.]

Have them start it up with the coolant cap off. Look for bubbles. Not good when you see them.

[myles]

the shop rang me today...they arent sure but its looking likely.The aux pump is leaking so thats one source for the coolant loss but their is a build up of pressue while running enough to bulge the radiator!

I had the same problem on my 525. The head was slightly warped causing a leak beween no1 and a coolant journal. The combustion gasses would only leak into the cooling system when the engine was under load, so there was no sign of problems at idle or without a load on the engine. The cooling system was under such high pressure that small leaks sprung up at the radiator and the water pump. The radiator cap was very slowly releasing pressure, but was not designed to accommodate this sort of problem. The cooling system would leak as the engine cooled. The leak would stop when the system pressure dropped a bit, but some considerable pressure would remain in the system indefinitely.

Solution was to skim the head and pop in a new hg. I did the value seals at the same time. It wasn't that big of a problem. Just looks a bit strange on first inspection.

[Paul in NZ]

i have been driving for weeks with it,It started as an occasional miss at start up,which became more frequent,then(i always have had a very slow coolant leak) the coolant top up became more frequent....I will ask them to do the combustion gas check.I dont know how else the system could get so pressurized.Howdo you check theexpansion tank lid pressure check?

[bsell]

i have been driving for weeks with it,It started as an occasional miss at start up,which became more frequent,then(i always have had a very slow coolant leak) the coolant top up became more frequent....I will ask them to do the combustion gas check.I dont know how else the system could get so pressurized.Howdo you check theexpansion tank lid pressure check?

Did I miss the part where you said how the spark plugs look?

My experience says the 'spies of the engine' will tell you much about what is going on.

Of course the steam cleaned 'spy' is the dead give away that you have an issue.

Also, did the rad cap pass its test? The old one may not be maintaining the correct pressure and may not be letting in air (vacuum break) as it should...

Brian

[Ross]

Did I miss the part where you said how the spark plugs look?

My experience says the 'spies of the engine' will tell you much about what is going on.

Of course the steam cleaned 'spy' is the dead give away that you have an issue.

Also, did the rad cap pass its test? The old one may not be maintaining the correct pressure and may not be letting in air (vacuum break) as it should...

Brian
Best advice here.
The plugs will tell and that rad cap should be relieving excess pressure. The radiator is already stressed so imagine the condition of your heater core. BMW recalled cars over heater cores bursting. The solution was a lower pressure cap.

[tim eh?]

Best advice here.
The plugs will tell and that rad cap should be relieving excess pressure. The radiator is already stressed so imagine the condition of your heater core. BMW recalled cars over heater cores bursting. The solution was a lower pressure cap.

If I didn't know for sure that my heater core was leaking a bit I would be totally FREAKING OUT over the disappearing coolant.

good luck with it Paul.

[Paul in NZ]

thanks guys.Plug five looks suspicious,i i def have to check the rad cap....does the expansion tank cap have a role to play here?(m30 remember)

[632 Regal]

does the expansion tank cap have a role to play here?(m30 remember)
thats the only cap my car has, I made sure mine was the lower pressure cap and functional. I get a coolant loss (not much) which I attribute to a leaky heater core.

[Paul in NZ]

confirmed,no 6 washed clean....at this time the head lloks fine,ie no craks or warps.Will hear soon re condition of valve guides n seals.Aux pump also leaking like a seive so looks like a call to BMA is on the cards(have already got a price on the pump and new heater vlaves)

[Paul in NZ]

she's back and sweeter than ever....well thats how it feels...shop didnt have the bill ready but i needed new rocker arms and the build up of pressure had damaged the radiator too.Not sure what else was done but the head itself was OK,no warps or cracks.Looks like the differential movement betwwen the old iron block and alloy head had reached a magic number.Apparently its not unusual for the radiator to actually bulge with the pressure.Have to take her back in a couple of weeks.Yay!I have to make aroad trip this easter too!1100 km!

[bsell]

Best advice here.
The plugs will tell and that rad cap should be relieving excess pressure. The radiator is already stressed so imagine the condition of your heater core. BMW recalled cars over heater cores bursting. The solution was a lower pressure cap.

Thanks!:D

I am glad the OP found a solution to his problem...open wallet and empty it into somebody else's hands!:(

Seriously, I wonder if the radiator cap took out the headgasket (and aux pump) or was it the other way around? All I know is, a new cap is cheap insurance for protecting the head gaskets and heater cores in these 'elderly' cars.

Brian

[bsell]

she's back and sweeter than ever....well thats how it feels...shop didnt have the bill ready but i needed new rocker arms and the build up of pressure had damaged the radiator too.Not sure what else was done but the head itself was OK,no warps or cracks.Looks like the differential movement betwwen the old iron block and alloy head had reached a magic number.Apparently its not unusual for the radiator to actually bulge with the pressure.Have to take her back in a couple of weeks.Yay!I have to make aroad trip this easter too!1100 km!

I noticed my year old radiator is 'thick in the middle' on the expansion tank side also. It causes me minor concern but I figure it will be allright as this is a 'town' car only now, no long trips for her when I have an '08 328 sedan in the garage.

And yes, I still like the E34's dash and controls layout better than the new car!;)

Brian

[Paul in NZ]

the car has a "recall cap" but of course it could be years old!.I will investugate further,but fro now she is as sweet as...did 1100 ks over the weeked,didnt miss ab beat no losrt coolant ,fule consumption back to normal too.