95 850 Turbo 5 Speed Motor May Be Finished But Not Sure

[dtmmoore2]

I am afraid I have let my baby down and she's heading for the scrap heap unless I can turn my luck around. I came across the following post and then decided to register with this web site to see if maybe there was a chance my engine is not beyond economical repair:

Healthy motor with no compression?
https://www.matthewsvolvosite.com/forums ... =1&t=45981

Engine was in perfect running order until one day last week. After a short drive I noticed my oil warning light had lit up and immediately pulled over and shut it down. I smelt and saw smoke coming from the engine and after checking the dip stick I added three litres of oil and when I started it up the oil light did not come on and the smoke stopped. I then drove approx 10 miles at 2000 rpm and eventually the oil lamp flickered and then came back on steady. I added another 3 litres of oil and drove home after finding the oil and lube shop had already closed for the night. Next day I drove at 2000 rpm another 10 miles and just as I got home the warning light came on.

This is when the farce began. Assuming that it was not good for the engine to overfill it with oil, I carefully added oil one litre at a time and checked the dip stick each time. I added close to five litres of oil and completely overfilled it because I was not reading the dip stick correctly (I expected to see dirty oil on the stick once the level came up but it remained clean and I continued adding oil). Eventually oil started pouring out from underneath (out of the intercooler perhaps) and when i started the car the dreaded white smoke came out the tail pipe. I immediately turned it off and got a mechanic from down the block to have a look.

I told my story to the mechanic and after checking the dip stick he judged that there was way too much oil in the engine and we pushed it to his shop to get the extra oil out and figure out what was wrong. The mechanic then put the car up on the hoist and let the excess oil to run out. He climbed a ladder to check the dipstick and eventually was satisfied, dropped the hoist and rolled it outside. He then told me that in order to figure out what was wrong he needed to recreate the situation whereby the warning light came on. I was told that due to the oil overfill, smoke would continue to exit the tail pipe for some time. I then drove the car with the windows down about ten miles but at highway speeds as I wanted to get rid of the smoky oily smell inside the cabin. The engine seemed to be running the same as always but just as I got back within a few blocks of the garage, the oil warning light started flickering. I parked and turned off the engine at the garage. A few minutes later I was asked to move the car and it wouldn't start.

We rolled it back into the garage and the mechanic took off enough parts to access the spark plugs. He checked the timing belt and I took a peak but it seemed to be fine. It was then that he noticed the coolant reservoir was empty and my heart sank. We filled it and coolant poured out underneath. He said the water pump had likely failed and that the engine had overheated. I told him the temperture gauge had not budged from its normal position during this entire episode. I have had overheating issues with other cars before involving leaking hoses and worn out radiators but besides the steam coming out from the engine compartment, temperature gauges in those cars have gone into the red. He told me that since there was no coolant, the guage had nothing to measure and that this explained why it hadn't moved into the red. He suggested that each time I had added fresh oil, this served to keep the engine from overheating until sufficient miles had been driven to have the oil warning light come back on. Over the next ten minutes while he played around with the engine, he had me attempt to start the engine. I cranked it for many seconds in total until the battery eventually died and had to be boosted. He then did a compression check and all the cylinders came in woefully below normal. He then told me the engine was likely seriously damaged and would have to be replaced. He didn't bother with an exact diagnosis.

I am obviously upset that the fact that the car had no coolant was not caught by the mechanic at the time he drained the excess oil out of the engine. Its also clear that low coolant sensor did not do its job for some reason (bulb is good). I am mistified as to why adding oil immediately on the three previous occasions the warning light came on kept the car running and I was able to stop and start the engine on several occasions during this period but this final time when the engine was running for no greater length of time with the oil warning light on as it did on the previous occasions, once I stopped the engine, that was it. The only difference being that the car was driven at highway speeds this final time rather than at low rpms. I am wondering why exactly an engine could be idling (albeit with the oil warning light on) for a few seconds up until the moment it was turned off and then refuse to start a few minutes later. One guess is that it has something to do with the change in engine pressures caused by stopping and then attempting to restart it or that there is sufficient temperature fluctuation during the process of stopping and then restarting the engine a few minutes later to finally "blow the engine". Does this make sense?

Given the post referred to above subject line "Healthy motor with no compression?"any insight as to what probably happened to finally stop the engine from starting and whether there is anything that might be done to get it to start short of a major engine overhaul (blown head gasket, warping of the engine that would require machining etc.) would be greatly appreciated. I have looked at the videos showing what is involved in pulling and replacing the motor or rebuilding the head and while I love my car and would be sad to send it to the scrap yard I would probably do better to buy another used volvo with a good motor if I came accross one in better overall condition than my own.