Blown Head gasket / Cracked head M50 Vanos

[MotoMan]

Hi all,

A big thanks to those who responded to a thread i started a while back. Those who can remember, i complained about a "missfire" symptom at between 2200 rpm and 3000 rpm. in addition the eng kept blown the tappet cover gasket(2).

I was advised to havecompression test done....and well after several overheating issed blamed on a faulty radiator, pipes, thermostat ect ect ect.... i had the compression test done.

Very little compression on cyl 5 and just a bit better on 6. 1-4 acceptable.

WHAT THE HELL DO I DO NOW ???

Where to from here any suggestions ? Any speculation as to wether it's the head or the gasket. my wife drove it last when it o/heated and i suspect she may have run it too hot! :(

The mach says the M50's tend to crack heads. If this is the case do i renew with a 528 head and turbo-charge and redo all the innards or what ??

Vehicle has just tripped the 300k mark.

Thanks in advance for all the advice.... And spot on for the previous....

Victor

[Mr. BILL]

First off, is it 300K miles or kilometers? If it's miles, that engine is probably pretty tired. I wouldn't dump a bunch of money into it. If it's 300K km, that's not quite as bad. If the car was driven any length on time, it (engine) could also be toast. A friend of mine tried to drive his home and cracked the head AND the block. New engine, big $$$.

Is it blowing coolant out the tailpipe really bad? Is there oil in the coolant or coolant in the oil? If the amswer is no, you may still be in business. You have a couple choices IMO.

You can pay somone (5 hrs) to tear it apart and find out how bad the head is and if the block is cracked, (hard to do though). Then, you'll know where you stand and can make an informed decision.

Or, you can do what I just did and with your miles it might be a good alternative. I bought a bottle of CarGo Seal Up at Pep Boys. I was very skeptical about this, but did some research that indicated this stuff might actually work.

It worked for me, so far at least. I still get a small amount of coolant into #3 cyl after sitting overnight, but you wouldn't know it by the way it starts and runs. I'd say, it's 98% healed. Huge difference. It's supposed to be a permanent fix. But, I'm just trying to buy some time until Ican afford a proper fix.

The key is to follow the directions EXACTLY as stated on the bottle. Making sure you get ALL the coolant out. I also let it idle for twice the time they suggest and let it air dry three times longer. Best of all, it only costs $4 a bottle. BTW, don't let the cheap price fool you the govt. tested it and others like it on cooling systems for neuclear reactors. The CarGo Seal Up was the ONLY one that worked.

If your engine has 300K miles on it, it can't hurt. You'll only be out $4.

[MotoMan]

Hi Mr Bill,

thanks for the reply. It is km's i appologise. I have considered the get someone to rip it apart and establish the extent of the damage.

But i may be able to get enough money together to send the car into a shop that does turbo conversions on bmw's. They have a standard swop out using the newer e39 528 head and then some work on the pistons ect including a turbo to kit it out. I have been toying with this idea as it would or should correct the head problem and offer me more power once completed. Just do not know if this is a route i should follow. Perhaps just repairing the eng to original spec will be sufficient. would enjoy the extra power though. Any comments ???

Regards

Victor

[MotoMan]

[Hey Bill,

I never quite answered u'r q's in the previous response. I have check all the usual, not oil and water mixing that i can see. No visible coolant seepage from xhaust, but definiate coolant loss albeit slow. Definiate power loss, that would be aro the cyl compression as low as it is.

what do u think of turbo'in the m50 ?

Regards

Victor

[Mr. BILL]

Try pulling out the spark plugs before you fire it up in the morning. If you find a wet plug, there's the culprit. A breach in the headgasket. Also, check the plugs after driving a while. I'm not a big Mod guy, so I'm not a good one to ask about adding a turbo.

[MotoMan]

Thanks bill.

I pulled the plugs to do the compression test. If memory serves me correct there were 2 that were fouled with oil.

I am just concerned that the head may have cracked. I suppose the easiest is to open her up. She is after all over 300k km. May as well do a full o/haul. Thanks again.

Can anyone mabe throw in their advice on the turbo mod ??? I am really not sure if this should be considered as an option.

BR

Victor

[Brett619310]

I have too questions related to this topic:

1) What is the symptom of a "misfire" or blown head gasket? What does it sound like when driving... I would want to know this to pull over and minimize the damage.

2) About how much does it cost to overhaul an M50 Vanos engine, assumming an honest, competent independent mechanic is doing the work? Would it be cheaper to swap it with another used engine?

No problems with my car yet, but I'd like to know in case I keep mine for another 150k miles.

[Mr. BILL]

Brett,

A blown headgasket will exhibit the following: Rough idle after a cold start. It will remain rough until temp comes up to normal and a white cloud will billow out the back until warmed up. It could also be hard to get the engine to turn over due to coolant in the cyl., increasing compression, If this gets too bad, you could damage the head, Also, oil in the coolant or visa versa, loss of power and overheating. Generally running crappy.

[MotoMan]

Hi Brett,

Agree with Bill. My symptoms were slightly different. Not too difficult to crank, but a vibration through the motor at between 2200rpm and 2700rpm, or therabouts. In addition the o/heating, no power (although sometimes it would feel like the car was running turboed), smoking a little on startup, first few seconds, higher fuel consumption.

Also we use leaded fuel and i cannot get the eng to burn the tail pipes grey. Def coolant seepage out the exhaust.

Hope this helps,

Victor

[me4mimes]

uh, oh.... thats not good... at that point i would start suspecting a cracked head or a cracked cylinder rather than a head gasket. check your oil levels and coolant levels! soon! my suggestion... if it is 300,000 miles is to swap out the engine. or just salvage what you $ can from your beamer and get another one.