BHG or Cracked Head - Likelihood?

[jgmoore]

98ti Sport Cali. Love this car. It is my baby. But alas, now I am sad.

Never had any problems with the coolant system. Regular SI and oil service from dealer, though I am due.

Cruising across the bay bridge on Saturday afternoon headed to a wedding. Stop and go until I got through the toll. While braking from 50mph to 25mph to prepare to exit, the car dies. It's still rolling along at 25 or so, so I pop the clutch and keep going - at that point I notice the temp guage on super hot, but no steam or smell yet. No noise. Shift to neutral and cruise until traffic forces me to stop. Its the freakin bridge. i don't want to be one of those guys stopped on the bridge. From a stop, I start the engine, comes to life and manage to get it off the bridge to the first safe spot I can park it. Less than 1 mile, revving just enough to keep it moving.

Call my gf, "hey, car died, you'll have to pick me up at fremont and harrison for the wedding". Waiting for her, I raise the hood, steaming now, but engine off and cooling. Look under the car - nothing dripping and I'm parked on a hill facing up. I'm all dudded up so I'm not messing around on the ground. GF arrives and its off to the wedding for cocktails. Lots of them.

Sunday morning, er, afternoon. SF police left me a note requesting 50 bucks for my non-permitted park job. Least of my worries right now. Bring along some 50/50 coolant. 1 gallon. Takes nearly all of it before it starts coming right back out the rear of the motor at about the same rate I was putting it in. Can't get under the car. AAA on the way. Take it to H Beck in Oakland. 1st time customer, but hear good things.

They diagnose a leaky connector and suggest replacing the thermostat as well. I agree, parts come from NJ for a Tuesday repair. They make the repair and try to pressurize the system. Won't take. Still leaking (but not sure how much pressure at this point). Didn't speak to the mechanic yet, but the word as relayed through the very-polite-while-serving-up-the-bad-news girl on the phone is that he's sure it is either a blown head gasket or cracked head. He seems to think the volume of coolant that is leaking during the repressurize indicates a cracked head.

Question to the gear heads here -> does that sound likely? And will he need to remove the heads to confirm one or the other?

My gut says the gasket is likely to blow first and would require a decent amount of driving with little/no coolant to crack the heads - and it might even sieze up before that happened. But, I haven't attempted anything more than an oil change since my 75 air-cooled beetle, so I'm by no means an expert. Hoping to get some feedback for anyone here that might have had a similar experience.

I'll be the first to admit that I don't check the coolant/level on a regular basis. Been relying on regular service inspection from the dealer and check of the temp guage to be sure all was well. Until Saturday, all had been well.

So, next question would be -> if it is a cracked head, should I replace or put that money towards a 6cyl swap? Me does like the 30mpg of the 4cyl.

All for now; I'll update this again once I hear back from the service shop.

BTW - first time poster (obviously), but lurked a bit from time to time. Honestly, never really had much trouble with the car. Take it easy on me.

[donslade]

Just went through a very similar experience.

There is a plastic connector for the cooling system at the back of the head, that is what broke, and that is why whatever coolant you fill it with will all leak out the back of the engine. Sorry.

Mine is currently at a local shop getting a new head gasket due to a warped head. No fun, lots of $$$.

Good luck,

Don S.

[mohaughn]

require a decent amount of driving with little/no coolant to crack the heads

Nope. Once that needle is pegged in the red if you keep moving the car for even a minute or two you can do severe damage to the engine. This is a common problem on M44s. There are two plastic connectors that are prone to break. The one at the back of the block seems to be much worse. Most people never see the steam because the water will pour out of the back of the block while driving. By the time it overheats there is no more water in the system. Once there is no water in the system the only place the heat can go is into the metal of the block and head. It doesn't take much warp aluminum.

There has been atleast 10 people on this site alone who have done severe damage to M44s by driving with the temp gauge pegged... And that is in the 2.5 years that I've been a member.

If that gauge starts to move even a little bit above 12 o'clock turn off the car immediately. Sitting on the bridge looking like a tool and waiting for a tow truck to move you from the bridge would have been much less expensive. But, you also have to make sure you stop in a safe place. Some times that can be almost impossible.

Best of luck with the repair.

[jgmoore]

Thanks for the feedback. Expensive lesson. I'm meeting with the mechanic in the morning. He said the labor to pull the heads is 10 hours. So, $1000 just to determine the problem + repairs of $200 for gasket set + $700ish for rebuilt head = $1900 min. Does this sound about right? He's suggesting I might want to consider a used M44 engine with less mileage - mine has 125k. But, I have always maintained the engine through dealer SI and oil service on or ahead of schedule. I do have 4 track days on the car, but other than that, I've been really good to it. I'm leaning towards taking my chances with a known 125k engine block than replacing the whole thing.

[jonchino]

Originally Posted by jgmoore

Thanks for the feedback. Expensive lesson. I'm meeting with the mechanic in the morning. He said the labor to pull the heads is 10 hours. So, $1000 just to determine the problem + repairs of $200 for gasket set + $700ish for rebuilt head = $1900 min. Does this sound about right? He's suggesting I might want to consider a used M44 engine with less mileage - mine has 125k. But, I have always maintained the engine through dealer SI and oil service on or ahead of schedule. I do have 4 track days on the car, but other than that, I've been really good to it. I'm leaning towards taking my chances with a known 125k engine block than replacing the whole thing.

WTF? It took me(a B machanic) mabye 2 hours to take out the head. I would shop around. Changing the engine would be less headache for your mechanic. I got to open a garage and chare these prices, I would be rich. wait I own a 318Ti, I am already rich hahaha.

[kensinva]

I just went thru this with mine, my wife overheated it pretty bad. I expected head damage too. But fortunately the head checked out fine, no cracks. Spent about $300 at the machine shop, resurfaced, pressure checked, checked for cracks, new valve guides. Reassembled it myself, probably about $500 ish in parts and materials. Running like a top now. I did replace all hoses, fittings, water pump, and thermostat also at the same time. So, your head may be ok, its a gamble. The garage prices do sound high, I would check around.