F451

Hey gang,

Newb here, looking to buy a 928, would be my first 928. I spotted what looks to be a well maintained and in generally great condition '84 (16v), with 84k miles, auto, lots of new parts, recent maint history, etc.

The seller tells me the car has a blown head gasket. It runs, but has a "miss". I haven't seen or heard the car yet, but looking at the forums, it seems like a blown head gasket is not unusual for the 928's.

My question is: when I look at the car, is there anyway that I can confirm the blown head gasket, or narrow it down to the gasket?

How about a warped head? I'm thinking I won't know if its warped until I pull it.

How about a cracked block? Would a simple compression test indicate if the worst happened and the block is cracked? Would it run with a cracked block?

If the problem is a blown head gasket and warped head, I can deal with that (time and patience as I'm not bad with a wrench and have my regular transportation so don't have to get the job done quickly).

But if the problem is a cracked block, of course I'd pass on the car.

Any tips on diagnosing the problem, or confirming the blown head gasket would be greatly appreciated.

Thanks!

Ed

ps: great forum. I've learned a ton already. And have always been a big fan of the 928. I can't believe how much car you can get for the money with the 928.

jeff jackson

Check the coolant...look for oil floating under your Coolant expansion reservoir cap. Check the dipstick, and look for any milky tint or a sheen on the dipstick... The compression test, will yield conclusive information regarding cylinder sealing.
The cylinder adjacent to the "blown gasket" is the culprit...and its pressure will be decidedly lower than the others. Hence ...the "miss". Very low compression, and the cylinder will misfire.

BC

Maybe some pressure into the spark plug hole whole checking for pressure on the cooling system?

Or the other way around?

Water in the tailpipe, (alot) can sometimes tell you.

Water in the oil or oil in the water.

It it a hard miss, like the car running on 6 or 7 cylinders, or an occasional miss?

Water in a cylinder will cause a MAJOR, ROCKING miss, especially if its in more then one hole.

jeff jackson

Yes ...low on coolant / high on "milky oil"...or "oily coolant", blowing a white cloud out the tailpipe... and missing...running with "dead cylinder"...will cause any, or all these maladys. Do the Compression test (typically done after the engine has been fully warmed...then all plugs are removed for the test)..but in this case, I should think whatever results are determinable... should be evident, even on a "cold" engine, so I wouldn't reccomend running it any longer than needed...to avoid the "hydrolock" possibility ...that was mentioned earlier in this thread. That would fubar your shortblock. So...not a necessary risk , at this point in the problem. Sounds to me, like you already "know" whats the problem...and are just seeking confirmation by majority. If it walks like a Duck... ,

Shane

Ed, there is also another great resource right in your neck of the woods:

http://autos.groups.yahoo.com/group/PacNW928/

You might even find some local guys willing to go with you to check things out. If nothing else describe the car to them and us as we might indeed know the car and owner. There is also a local mechanic in Woodinville that could do a thorough PPI on the car for you.

karl ruiter

Lots of 16 valve US Ljet motors on ebay for very little $, so if it was anything besides just the gasket you might want to think about going that way. Although, the 16 valve US cars don't really bring a lot of money, so you might just want to buy a running car instead.

Imo000

Whatever you do, just make sure the car is cheap enough to include the cost of all the possibilites. Changing an egnine is easier than pulling the heads and the heads will come off with the engine in the car.

If you can, pull each spark plug, the one that's the cleanest will have the coolant leak.

SteveG

Just wanted to say I don't think blown gaskets and cracked heads are common problems with any 928 that was maintained. It happens, but generally the engine is not prone to this. The only weak link is the TBelt and electrical gremlins, both of which are correctible thru this forum.

checkmate1996

Unless your mechanically inclined, gots lots of time and extra $$$ laying around your house and you can buy it cheap... go for it...

jpitman2

I would check easy stuff first - check rotor buttons, dist caps, rubber belt inside distributors etc...Bought a misfiring car cheaply once on the punt it wasnt a head gasket - and it wasnt - just very old fouled plugs.
jp 83 Euro S AT 50k.

Oscar M

Have no fear...it may seem like a Goliath of a task but in reality, it's not so bad. Shops will have you believe that this is something best left to pro wrenches but having gone through it, it's really not that bad. The most difficult thing will be getting the engine in and out if needed. I say if you can get the car cheap, and you don't mind getting your hands dirty, it will be a very rewarding task.....especially when you get the engine to start for the first time.

atb

Ed,

You A Hare Scrambler? What's your weapon of choice?

As Shane noted, we've got a strong 928 contingent in Washington. If you want some help looking the car over, post here or on the PacNW yahoo groups site.

John Veninger

Buy the car really cheap and then buy my motor for it

bd0nalds0n

Expenses on these cars sneak up on you. I would never again buy a fixer upper. The investment of time, money, energy, frustration is too great for what you end up with after the fact. Far wiser to take what you think it will cost to fix a beater, triple it, and spend that money on a well-maintained example. You'll still be dollars ahead, and you'll get to drive the car rather than be under the hood (or behind the dash) all the time.

F451

Wow! You guys rock. Great suggestions everyone. I really appreciate the feedback, its very useful.

I am still trying to decide just how much time and $ I am willing to spend to fix something up, vs the very good suggestions of just spending the $ upfront for a car that is in better shape.

I think I am going to look at the car to see for myself if I can determine exactly what is wrong with it. The current owner says the head gasket is bad, that it runs, but misses.

He also described a lot of $ that he recently put into it, but has a bunch of other vehicles and projects going (I can relate to that - just thinned my herd of a Ducati and a 240Z), so he's going to let the 928 go at a price that will cover his recent expenses on it.

I'm a bit of a glotten for punishment though, so doing a bit of work on it and spending some $ doesn't worry me to much.

I'll keep you guys posted about what I learn if I go see it.

Thanks again! -Ed