Hello, and Happy New Year's.

I recently inherited a 1988 240 dl. Its in pretty amazing shape for sitting as long as it has. The main problem is low idle, and getting up to speed once its warmed up. I figured that it just needed some TLC and took it to a local mechanic for a much needed tune-up. He called me and said that he had bad news...one of the cylinders had a compression reading of 75 or 85 and it should be more like 120. Now I don't know as much as I should about car mechanics, but I feel like if the engine had compression problems, it would have more evident symptoms. Currently the symptoms are: Low idle, reaching a passing speed or speed up long hills, and rough idle/shaking. The engine does not leak any fluids. No oil on the ground. No oil on the engine. No black smoke. No blue smoke. I drove it yesterday over 100 miles averaging highway speeds of between 60 and 70 miles per hour.

Im hoping that someone with 240 knowledge can help me with a sight unseen diagnosis.

Thanks

 

Compression is needed for a piston to fire correctly. All of the symptoms are symptoms of low compression or a cylinder missing. If you have low compression in 1 cylinder and that cylinder is not firing properly, you are likely without 25% of your preformance.

Old cars sitting parked somewhere is the worse thing for them. I had a lady park her Lexus for about 9 months because it was overheating. I fixed the over heat problem and the same days the oil pump failed. Three days later the motor seized.

There is a good chance that a piston ring got stuck or slipped down the piston and that is what is causing the low compression. At any rate, a motor swap is in order. Sounds like the cost to repair the motor will exceed the value (cost) of your car.

When someone buy's an old car, they should check compression because it's the best indicator of the health of the motor. The sad thing about most old car purchases is that the true condition of the car usually shows up between 50 and 100 miles of ownership. I'ts ahrd to take a 50 mile test drive but it really is needed on anything older than 10 years. That and the fact that you have to figure out what causes rough idles, CEL's, hard starting, etc. before you pull the trigger. Unless of course you're a good mechanic and the deal is so good even an engine replacement will make it worth your while. I personally would not mind replacing a motor in a car that has a great body and interior. Kinda like dating a good looking crazy girl. LOL

 

Thank you for your response. Im taking the car for a second opinion tomorrow. Im hoping that the cylinder is not as bad as Im told. Can you still drive a car with one bad cylinder? Mostly city miles. No long trips. Just curious.


Thanks

 

You can drive anything that you can start and keep running. A bad cylinder will usually result in unburnt fuel which leads to other problems including a damaged cat. You can drive it till it drops I guess.

 

Ask the wrench what happened to the compression when he put some oil in the cylinder.
If he didn't, try it and see what happens. This engine does not have sleeves.
If the reading goes up on that cylinder, it could be a stuck ring or worn cylinder wall. If there is no change, it could be a valve lash problem that could be adjusted.
If the engine isn't consuming gobs of oil and isn't smoking, I'd lean toward a valve problem. A good mechanic will test well before offering an opinion or several opinions.
Ed

 

Thank you Ed7. Im keeping a positive attitude. I will be taking the 240 for a second opinion tomorrow. Ill post what happens after. Thanks again for all imput.

 

....Turns out the first mechanic that I took my Volvo to was WRONG!!!! The compression was fine. One of the spark plug wires had a disconnected connection in cap. If that makes sense. The 2nd mechanics exact words were, "You just need a tune up". Just as I thought. He replaced the spark plugs, the wires from distribution to the plugs, the gas filter, the air filter.....Which by the way, the air filter was so bad he thought that it may be the original air filter....., and the most expensive fix was the fuel injector. It needed to be replaced.

Now I haven't taken a car to a servicing in many years, but all in the mechanic took me in without an appointment, worked on my car in between all of his other clients, let me stay and watch, and with parts and 6 hours roughly of labor....400 dollars. I gave him a 10% tip. He said the tune up was 250 and the unexpected fuel injector was 150 for the part(new)and installing it. Im sure he padded for himself and crew of 2, but im happy.

End result....The car runs amazing! NO low idle, NO lack of speed, NO skips, NO bogging down, NO ticking or clicking, or muffler skippage, NO overheating, NO shaking, NO stalling.... fantastic.

Thank you again for all knowledgeable insight and info. This forum is great...

Thanks

SVEn

 

Air Filter from out 1988 240 dl one day ago...