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-   -   Heads and Gaskets guidance (https://rennlist.com/forums/928-forum/774101-heads-and-gaskets-guidance.html)

Simon928 08-31-2013 11:54 AM

I'm in the midst of doing this exact same thing on my 84 auto. First time for me too.

https://rennlist.com/forums/928-foru...l#post10722471

I only have a single car garage and thus have very limited space, so I pulled the engine up, pushed the car out onto the driveway, and then put the engine down and on a stand. I'm actually about to go into the garage to try and clean off these damn cam tower gaskets. What a bitch to get off, my goodness. I'll probably spend all day doing this, maybe more.

I can't really comment on how difficult it would be to remove the heads with the engine in the car, but I can only imagine it would be quite a pain, especially if you've never done it before and don't know what hidden bolts you are looking for. That being said, it apparently can be done. I need to replace my motor mounts and oil pan gasket and give the engine a good cleaning as well, so pulling the motor made the most sense in my case. It's not terribly difficult to do either...if I can do it, anyone can, and that's not false modesty. I can pass along a checklist of things to disconnect. It took me about three evenings to complete, and I am a slow working noob.

AirtekHVAC 08-31-2013 11:58 AM

I'll be doing this probably next winter myself....I want to refresh it, and clean the engine compartment and prep for paint.

Imo000 08-31-2013 12:02 PM

The factory head gaskets are very good at what they do. There is nothing wrong with their fire rings or the materials they are made from. It held up for 30 years, isn't that enough. There are engines with some really nice HP that still use OEM gaskets with zero issues.

Mrmerlin 08-31-2013 12:21 PM

you should pull the engine then refresh the engine.

Buy a Victor Reinz full engine gasket set,
also get a silicone pan gasket and a new Laso waterpump.

NOTE your going to be into this repair for about 2000.00 ,
with all of the parts and the machine shop work , and you doing all the work
make sure the heads get magnafluxed for cracks

Wisconsin Joe 08-31-2013 12:25 PM


Originally Posted by LazerSquid (Post 10725245)
MP; You have absolutely no idea how hard I've been looking for those manuals!! Thankyou so much. I downloaded all of the different sections (I think I have about 3000 pages of information to read now haha)

TFO; I don't want to pull the engine because I don't really have the means to do that. Is there not any way that I could remove the fenders or something instead? That seems a lot more feasible for my situation.

Did you read the "Read this First" sticky yet? The reason I ask is because there are links to the WSM downloads in it. Links to a lot of other helpful and useful info too.

Why can't you pull the motor? No space? Nowhere secure to keep it?
"Don't have the means" doesn't say much.

Unbolt everything, get it ready to pull. Rent or borrow a hoist for a day. Buy a stand.

Far, far cheaper than paying someone else.

And if you go back to page 2, you will find this:

https://rennlist.com/forums/928-foru...ggestions.html

Head gasket on an 84. He has decided to pull the motor. It has a lot of useful stuff.

Another one is this:

https://rennlist.com/forums/928-foru...r-warning.html

It's not a head gasket, it's TBF and bent valves. But it's about pulling the heads with the motor in the car. Lots of pics, lots of useful stuff.

Edit to add: While I was composing this, Simon chimed in. He's the first thread I linked (the one on page 2).

LazerSquid 08-31-2013 12:34 PM

I took a video today of the car, I was moving it to a more covered area before I do the work to clear out the cylinders, when I noticed it was performing and acting a lot better than it had been. Here's the video, let me know what you guys think

If it ain't broke, I'll fix it 'til it is

LazerSquid 08-31-2013 12:40 PM

To be honest the smoke is looking a lot less like coolant and a lot more like oil smoke (similar to my old two stroke bikes) and it smells like uncooked bread dough, kinda yeast-y maybe? I'm not trying to convince myself that it isn't the heads but none of the problems are being consistent.

If it ain't broke, I'll fix it 'til it is

MainePorsche 08-31-2013 12:46 PM

Lazer,
A question.
Does your oil have coolant in it, or does your coolant have oil ?

Also, if you have ATF leaking by the cats you need to address that for safety reasons.

LazerSquid 08-31-2013 12:49 PM

MP; I know that the ATF is flammable and I've read the stories of cars catching fire from neglected leaks down there, so that will be the next thing I fix. I have a great hydraulic shop I. Town I'll take them too. Also, there are little spots of what appear to be oil in the coolant resevoir, now that you mention it. Why?

If it ain't broke, I'll fix it 'til it is

MainePorsche 08-31-2013 12:55 PM

Defect in the oil cooler ?
or
Head gasket as you suspect.

LazerSquid 08-31-2013 01:20 PM

If there's oil in the coolant or coolant in the oil, why would it be smoking? Neither one should be in the cylinder right?

If it ain't broke, I'll fix it 'til it is

dr bob 08-31-2013 01:23 PM

You'll know it's coolant because your coolant level will be dropping. Coolant in a cylinder leaves a plug very white, as it's being steam-cleaned.


Do a compression test on the engine and see which cylinder is leaking if any. If you aren't familiar (you should be with motorcycle experience), do the test with all plugs out and throttle propped open, fuel pump and ignition fuses pulled.

Do a leakdown test with each cylinder at TDC. The leakdown test lets you listen to see where the test air is going. You'll notice the air coming out through the coolant bottle if theres a leakage path there, otherwise intake and/or exhaust and/or crankcase noises tell you about where it's leaky.


If you decide that the engine needs internal work, pull the engine and put it on a stand where you can work on it. There's plenty to do and there's hardly any room to work with the engine in the car. Some might brag that they did a head gasket with the engine in place, but I can tell you from experience that it's a ton of extra work trying to do it in place. Lots of opportunity for collateral damage to the car. You'll have the chance to properly clean everything so less risk of contamination. You'll be able to inspect things too.

----

Head gaskets don't just blow on these cars without some related issues. Getting the engine hot enough to warp a head and cause gasket failure means the head is likely warped. There are known longer-term issues with cooling system maintenance and corrosion that can contribute, and require repair or rework of heads and block to replace missing metal. The bores are critical, and if they are scored or out of round much, the rework costs can easily exceed the value of the car.

You mention that you'd have to save up for repairs, so I'll warn you now that you are heading down a very slippery slope on 928 parts and possibly labor costs. There's a JB mantra that says that "you are ten thousand dollars away from having a five thousand dollar car", and that applies to folks who find a car that's reasonably sound to start with. When I look at a 928 for someone, I start off with a $5k number for replacement of rubber and other known age-related wear items needed to make any 928 safe and reliable enough to drive. That's just the parts budget, and it probably needs to be revised up some. Then deduct for stuff that's been replaced recently. Again, assumes a car that's otherwise mechanically sound. So think carefully about the costs in dollars and time that will be needed to make the car 'right', at least to the point where you would be willing to own and drive it. I preach that the cheapest 928 to own is the one that's perhaps the most expensive to buy, the one where the loving owner has been religious about maintenance care. Unless you cherish the restoration and repair work as therapy (as I sometimes do), you should consider letting this car go as it is, and finding the 'right' car when your budget allows.

Bill Ball 08-31-2013 01:34 PM

If it's ATF you should get red drips at other times and ATF should run down the hose and lines and you should see ATP coating the lines and heat shields in that area. The "white smoke" looks like it's steam leaking out of the exhaust. You should be able to determine if that is so or it is external. Also, if the AC is on, the evaporator box drains exactly in that area above the cats, but you will hear "drip/sizzle" with any external fluid leak onto the cats when you turn off the motor and the steam is not constant as yours appears but intermittent with each drip.

It's common for head gasket leaks to vary depending on engine temp and stress.

ptuomov 08-31-2013 02:26 PM

I am running factory head gasket at 700 rwhp on an S4 and it's not failing. I think you can find bigger problems with the motor, if the 16V motor has the same kind of gasket.

Mrmerlin 08-31-2013 03:25 PM

I think we need a definitive description on what the smoke smells like if it smells sweet then its coolant if it smells like oil then it could be oil getting sucked into the intake from a misrouted hose or you have a lots of blowby from the rings a compression test will confirm this


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