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Hello fellow Rennlisters.
My '91 C4 is suffering at the moment, and I need some advice. After over 3 years in hibernation, due to.. well, life got in the way, I'm getting the motivation back to continue with my project car.
For those interrested, my original build thread is here: Project Green With Envy
To continue my hunt for oil leaks, (what stranded me 3 years ago), I got the car up on stands, removed the exhaust, manifolds, rear engine plate, engine mounts, to get to the rear timing covers.
Removed both, and they were definately one(two) of the sources.
When getting ready to remove and replace the next culprit, the "block-to-oil filter housing" i found some new/old potential leaks. (see photos)
My question is; At this stage, is it easier to pull the engine, hopefully without gearbox, and do a proper reseal?
I have a shed in the garden I can use for the rebuild/reseal, allthough it will get cold for me in the winter time. + my gf will probably freak out if i pull the engine. (I haven't discussed this option with her yet)
If you guys recommend an engine pull, I'm thinking of doing a reseal or rebuild, based on your responses.
Background info: Engine is at 264k km / 164k miles, with no previous documentation on a reseal/rebuild. Only a service book with general maintenance to 210k km / 125k miles.
I see a lot of carbon buildup through the exhaust holes in the block. Is this a telltale sign of worn rings?
Also there seems to be oil coming from the heads in the pictures.
Pics:
Help would definately be appreciated.
I know there probably isn't a definate answer to this, but feedback from you experienced lot would make me happy.
PS. Please excuse my english. I'm Norwegian.
PPS. Last pic of my car for reference.
Fix the leaks you can see and get to. Put the car back together and drive it.
When you are ready for a real rebuild...pull the motor at that time.
There isn't really much to worry about if the motor is weeping . If you have a real deep puddle of oil. That needs to be addressed. But if it doesn't splash when you step in it, and if you aren't going to dive in and rebuild the motor without any breaks- meaning start and work every day until done...just get the majority of wetness taken care of and wait.
You will be surprised how many oil leaks you can address with the engine in the car. The are a number of good write ups out there. The usual suspects are in no particular order:
Timing chain covers
Valves covers
Oil bridges
Chain tensioner covers
Oil pressure sensor
Oil temp sensor
Oil lines
I just did all of these without pulling the engine and with bumper in place. Unless you steam clean the engine you may get some residual oil drips when the engine gets hot.
Your engine looks a lot like mine did several years ago . I though had a few broken head studs so dropped the engine pretty easy thing to do. To me your exhaust ports don’t look bad at all the valves look pretty good. I think though I am with the fix the leaks crowd though and drive it you can always do a rebuild latet
At that milage, if you plan on keeping the car for a while I would just get a full rebuild over with as soon as you can afford it. You will enjoy the car much more with peace of mind, keep the girlfriend happy (as long as she doesn't see the bill), and keep you out of the cold.
I bought a higher milage 964 and rebuilt the engine before I ever drove the car and I couldn't be happier that I did.
Otherwise as others have said, it really depends how much it's leaking and or burning. If the leaking isn't horrible and the leak down numbers are good there is nothing wrong with an engine in or out reseal.
How many miles since last valve adjustment? I would do a leak down and compression test. If it needs anything do it now before something fails. It is far more costly to do repair than do a preventive rebuild. If it checks out and valves are OK go to post #2
When I bought mine, it had run 250,000 km and dripped oil everywhere. I did a thorough inspection and replaced all necessary hoses, gaskets, etc. This was done with the engine in the car, during a winter. Now the engine is completely tight. Went down from an oil consumption of over 0.5l per 1000km to 0.3l per 1000km. something I think is acceptable for an old engine. In the autumn, I am going to switch oil from the synthetic 10w60 to mineral oil 20w50, then I expect oil consumption to go further down.
Great response, guys.
Thank you so much. I think I've made up my mind.
I'll fix all the obvious and visual leaks and degrease/steam clean the engine after I'm done. That way I'll be able to get all the old oil leaks and crud of the engine.
Then I'll run it on jackstands in the garage and check for more leaks. Then I'll drive it, and do a leakdown test, to see the condition of the internals.
Last valve adjustment was done 3 years ago, but the car has been driven maybe 1 mile in total since then.
After all, it only takes me a few hours of work to remove the parts i have off right now. I guess my thinking was a bit "while your in there, let's pull the engine"
Anyway. Thanks again for your qualified answers. I really appreciate it.
This forum rocks!
I wouldn't rebuild unless you NEED to rebuilt, at that mileage you may need to, but it depends. So get a few of those leaks fixed, adjust the valves, do a leak down as Cobalt stated, and drive it. if it smokes, makes weird noises, or leak down/compression are poor, then its time. Rebuild is a big project and $. Replacing gaskets much less so.
If you pull the motor, personally I'd do a top end because well, motor is out, along with replacing fuel lines, all rubber bits, oil lines needed, etc.
08-14-2018, 04:20 PM
Need advice; Time to pull the engine?
