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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
1989 5.7 TPI
Tracing an oil leak the car doesnt get driven much and sits in a garage. But it has had an oil leak since I can remember. The starter is covered in oil and so is the oil pan and tranny. I took the converter cover to take a look at the rear main but cant tell if thas the source of the leak. Driver side engine block looks pretty dry. Passenger side towards the rear not so much. Ive read the dipstick may leak, I can move the dipstick tube in and out of the engine block with no effort, is that normal?
definitely address the dipstick tube first. I recently tracked down an oil leak to the oil pressure sender behind the intake manifold, it was causing oil to leak down my engine and drip off the starter bolts
definitely address the dipstick tube first. I recently tracked down an oil leak to the oil pressure sender behind the intake manifold, it was causing oil to leak down my engine and drip off the starter bolts
On an 89 wouldn't the oil pressure sending unit be above the oil filter on the block?
First place I'd check is the valve cover bolts. For whatever reason, they tend to work loose, don't ask me to explain why.
The rear main and rear of the pan gasket don't look too bad, they're not dripping, which usually if they were leaking more than normal i'd expect a visible drip. The oily mess seems to extend forward on the block, so look further forward. Check the front cover seal around the balancer, for example. Check the intake gaskets. Visually poke around until you see the obvious AH HA! source of the leak.
The dipstick tube shouldn't move because it should be bolted under one of the exhaust bolts with a welded tab that keeps it from coming out. IF the bolt is there, and you can pull the tube out, that'd be bad. If you don't see a visual indicator of lots of oil around the dipstick tube to pan connection, it's probably not the source of your leak.
Think of it this way, compared to a pre-86 SBC, that's not even a leak. It's insignificant from that viewpoint.
On an 89 wouldn't the oil pressure sending unit be above the oil filter on the block?
First place I'd check is the valve cover bolts. For whatever reason, they tend to work loose, don't ask me to explain why.
The rear main and rear of the pan gasket don't look too bad, they're not dripping, which usually if they were leaking more than normal i'd expect a visible drip. The oily mess seems to extend forward on the block, so look further forward. Check the front cover seal around the balancer, for example. Check the intake gaskets. Visually poke around until you see the obvious AH HA! source of the leak.
The dipstick tube shouldn't move because it should be bolted under one of the exhaust bolts with a welded tab that keeps it from coming out. IF the bolt is there, and you can pull the tube out, that'd be bad. If you don't see a visual indicator of lots of oil around the dipstick tube to pan connection, it's probably not the source of your leak.
Think of it this way, compared to a pre-86 SBC, that's not even a leak. It's insignificant from that viewpoint.
I had previously replaced the oil sending unit above the oil filter thinking that may be the culprit as it was drenched in oil but it turned out to not be the source. Just double checked the valve covers bolts they are pretty snug and no obvious signs of leaks. Now I am thinking it may be the oil pan gasket or the diptstick tube. I dont see a tab for the tube it may have sheered off for some reason. When I purchased the vehicle the previous owner had the engine rebuilt but this was over 10 years ago and in those 10 years I have only logged 30k miles on it and its always had the small leak. The stain the garage is maybe a 5" diameter and the car hadn't moved in 3 months. Will look into a new dipstick tube solution and cleaning the underside.
Quarter car wash. Pick up acoupla cans of "engine degreaser" on your way; soak everything with that real good; then blast it off with the high pressure. Being careful of course around electrical things.
If it were mine, I would pull thw tube, clean everyhing with acetone, lacquer thinner, or a similar solvent, then apply a coat of LocTite 620 and maybe a small O-ring at the swage of the dipstick tube, then ram it home. After a cure, clean up the mess and monitor for more leakage.
The tubes slide in/out fairly easy. Needs a touch of sealer and bolt tube in securely.
You could do a rear main and pan gasket if you want to, they are old if they are original.
Pick up acoupla cans of "engine degreaser" on your way; soak everything with that real good; then blast it off with the high pressure. Being careful of course around electrical things. 
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