Dan in Pasadena

My well-sorted '87 has blown its headgasket - I think.

History: 59K when I bought her in 04/01 from original owner, sister-in-law. Almost no records. Owner was the "fix-it-when-it breaks" type (eek!). Car was sitting in a garage for the prior 6-1/2 yrs! Cheapo discount tires - flat spotted. Spent $$ replacing all belts, hoses, fluids, filters, battery, tuneup. Later - brakes, clutch, rear axles, motor mounts, AC, alternator, and more. I let it go 40K miles before again replacing belts, T-stat, waterpump and front oil seals. While there swapped to a clean radiator overflow tank. Recently installed full polished 16" PD's, polished cam tower, chipped it, tuneup with 8mm Magnecor's - you get the idea. I spent way too much on this car.

Recently she showed some coolant loss, I didn't think much of it -stupid! Again noticed it and no evidence of leaking -running fine at this point. Then, rough idle at starting after sitting a week, but "cleared out" in a minute. After sitting a week, started her - again the rough idle. Took her out and ran her up through the gears mildly, running good but started POURING smoke out the back. So bad I thought it was a fire and pulled over expecting the worst. No fire, no leaks, nothing - coolant tank empty. This has GOT to be a blown head gasket, right?

So......while I'm there.........what to do? No time to do it myself, what will the headgasket replacement cost, ballpark? If I go for a valve job? It will increase cylinder pressures in this now 103K car, so is it shortening the life of the rings?

Last, I know the install of the FR Wilk chip remapped the fuel system (bumped timing?). Could this have been a contributing factor? The car runs undeniably stronger with it, not drastic of course but better. I drive this car mildly - not Grandma, but calmly. Not a kid. Occasional hard runs up through the gears.
All help appreciated. Man, I've got too much money into it. If it were a 951(!), but it is a good car, can't stand the idea of NOT doing it right.

Tony K

Have the oil cooler seals replaced while it's all apart. If the car were together and running, it would be an $800-$1400 job to have done because of all the time/difficulty involved in taking everything off around it. With the head off, it's almost "easy", and it is only a matter of time before it will need to be done.

You didn't mention the condition of your oil - hopefully it is just one of the rings in the head gasket, and not an oil passage, too..(?)..

Good luck, and nice work taking care of an NA!

hacker-pschorr

1. Valve guides
2. Does Cometic make a head gasket for 944's? If so get one.
3. Valve job
4. Ditto on the oil cooler

I know there is one other item, I'm a bit hung over to think at the moment.

fezz

dan,
when you first noticed coolant loss - how much was it going down, in how many miles?

Dan in Pasadena

Tony, Hacker and Joe, Thanks for the advice on the oil cooler seals. I wondered about that. But since mine had never leaked in 103K miles I wondered if I would be better off leaving well enough alone? But you are all saying to go ahead with it, huh? Okay.

Tony, not sure what you're getting at by your comment about the "condition of my oil"? Are you asking if water mixed with the oil? Doesn't appear so. As to the oil cooler seals, I am not familiar with how they look? Are they just some sort of simple O-ring, or more complex? My question is: Do they just harden and eventually not provide a seal? So then are new ones just more pliable or "giving" in providing a reliable seal to prevent the oil/water mixing that everyone (except me so far!) keeps talking about?

Joe, What is a "Cometic" head gasket and why do I want/need one? What is everyone's opinion as to brand of gasket & type of gasket adhesive, if any? Is this akin to a "widefire" head gasket the 951 guys are always speaking of? Which I assume just provides a crush seal or better resistance to the increased cylinder pressures those engines see?As for valve guides, I am going to assume they are simply press fit silicon bronze(?) I have no issues with oil usage (so far) but recognize this may be cheap (hopefully) insurance. I'll ask about it as a part of a valve job. Anyone with experience with a 3 or 5 angle valve job? Worth the extra? Better sealing, but it IS an NA, so do I need it?

Last to Joe, Not sure the amount on the coolant leakage. Within a week or two of having the T belt, water pump, T stat, front oil seals done I noticed it was running a little hotter than it did before. My wrench said he may have inadvertantly used the hotter T stat and would change it out if I were concerned. I told him I'd watch it. At that point it had used about 3/4 the coolant in the overflow tank. That is 3/4 between cold fill and hot max levels. Why is the amount at that point important? As to miles? Minimal...guessing here, but maybe 200 or so. Thanks for the fast answers guys. Much appreciated, Dan

Dilberto

Dan,

Take a small sample of your coolant out of the overflow tank, and hold it up to light- can you spot a light oil slick? Thats the beginning of the engine's end....if the oil cooler seals are ignored. Also, check and see if all hoses, water-permeable sensors, and coolant bleed screw is on tight. I am guessing your NA has lived with a huge bubble of air in the system for some time. Either that, or the paper-thin water jackets in the radiator have fused shut, leaving less passages to cool water(clogged deposits). This is why German cars have aluminum/plastic in the cooling medium- they specify to use distilled(over-boiled) water in those units for that reason only.

An air pocket will give false overheating alarms too, because air expands by heat. Water evaporates from it. There is a hidden air inlet somwhere in the system, that presents you these issues. Do a thorough cooling system pressure check to find out. Then, eliminate all possible players in the cooling system matrix, one-by-one. Somewhere, you will find the unlikely culprit. After this experience- you should be so versed in this diagnosis, you can easily answer questions, and possibly moderate discussions on the subject.

hacker-pschorr

Cometic is just a brand name of MLS gasket's. I'm suprised I don't hear about these more often: http://www.dupont-dow.com/Products/Viton/head.asp MLS gaskets are a triple layer steel gasket. Every new Audi and VW turbo has these stock. Check out some VW & Audi sites, head gasket failure's on even the highest pressure turbo motors does not happen. Do you "need" one on a NA 944? No, if they make one should you buy it? Sure, why not put the highest technology in there now that it's available?
Tim Murphy had a Cometic made for his 928 running 14psi with a Vortec pushing 550hp to the rear wheels. So far so good.

My mechanic explained to me a 3 angle valve job is nothing specials, just a "regular" valve job, I'm not sure how much better a 5 angle is. Should you get one? I would.

hosrom_951

Replace the two sensors on the head.

Valve job

Gaskets (the FULL set) for the head

Oil Cooler Seals

Belts/rollers/front seals.......

You should be fine.........

The valve job w/guides is not so important if everything is ok up there.

hacker-pschorr

I seriously doubt a 103,000 mile head won't have at least worn exhaust valve guides. I've seen two 944 engine's apart with less than 60k with worn valve guides. It is possible his are ok, but unlikely. Once the head is apart, not that difficult to check.

Dan in Pasadena

Thanks everyone.
Hacker,a 3 angle valve job is NOT a regular valve grond, at least not on American cars. I know- I've done them myself in my distant, more hands-on DIY-er past. Besides, I don't have access to a valve grinding machine anymore. A 5 angle grind is something else altogether. I hear about them a lot in American cars mags, not sure of the specifics but the intent is a better seal. Probably not necessary at all on an NA.

As to the menton of a water bubble. That is the first thing I thought of when my car began running hot - that the Tbelt, waterpump, front seals job I had just had done had left a slight bubble. Maybe/maybe not. I won't know now. Now all I can do is get the headgasket pulled....if that's what it turns out to be. I'll post the resutls when I speak with my wrench this afternoon.

Thanks again everyone, Dan

hacker-pschorr

Could be, just going by what my mechanic does. When he says a valve job, this is part of the deal. Maybe he was talking about all 944/Porsche's? I just remember asking if they were doing a 3 angle valve job or just a standard one. I was told a 3 angle was the standard valve job.

Danno

"What is a "Cometic" head gasket and why do I want/need one? "

Dan, check out my Headgasket Dissertation paper on the GURU Forums - Headgasket. I carry the Cometic all-metal headgasket for 944NA cars. It'll be the last gasket you need. However, you should track down the cause of the failure, if possible (several causes pinpointed in my dissertion PDF).

Also manual gives specs for 3-angle valve job. With modern equipment, you might as well get a 7-angle job or a fully-radiused contoured valve-job (flows better than 3/5/7-angle valve grinds). Doesn't cost any more than a 3-angle valve job either.

Dan in Pasadena

Danno, Can't access you dissertation from this PC, my work PC. I'll try again from home.

Haven't read it yet, but why is an all metal, all steel presumably, headgasket NOT a problem on an all aluminum block/hed? Aren't there differing coeficient of expansion rate issues or electrolysis issues? I like I said, you may address it in your dissertation, but I just thought I'd ask.

Legoland951

It sounds like a definite head gasket if it blows lots of white smoke out of the exhaust (steam). It should smell sweet (antifreeze) and compression/leakdown test will be the final test to confirm. Head gasket is not too bad to do yourself if you are mechanically inclined. I believe 3 angle is the factory spec valve job. I would call another head gasket party but I have a 924S being taken apart in my garage and my 83 944 just died last night for some reason (first time a 944 left stranded anywhere that I could not repair or limp home). You been to my place before and I will be happy to help with advice or a head already machined to put on immediately after you take it off your car (no downtime waiting for the machine shop). If you don't still have my number, PM me.

Peckster

It won't increase compression by much, I doubt it would shorten ring life.