Oil leak problem



hey i have a volvo 740 gle 1990. it has probably about 235,000 miles on it(i’m not sure the odometer broke at 208,000 miles a year and a half ago). i haven’t changed the oil in over 30,000 miles so i decided it was about time to get the oil changed. now the engine is smoking obviously from an oil leak somewhere. the car ran fine before i changed the oil and now it looks like it may have a couple leaks. it smokes a lot. i don’t want to get rid of my car because i am in love with it. i was wondering though how much oil leaks cost to get fixed, and why all of a sudden after the oil change it started leaking. can someone help me please???


You seriously went 30,000 miles without changing the oil? I hope that’s a typo and you meant 3,000.

Some of the more common places for oil to leak are: loose oil cap, valve cover gaskets, double-gasketed or loose oil filter. Since it’s smoking, that means the oil is dripping onto hot exhaust somewhere and any of the above could do that. I’d check the cap and filter first since they are dealt with during an oil change, and this didn’t start happening until after that.


Next time it is smoking, open the hood see where it may be coming from.

Assuming it is not from the exhaust, ie out of the exhaust.

Does this one have a Turbo?.
Next, take it for a drive, then leave it to idle in the driveway for 5~10 min while you check for oil drips underneath.
I, also, suspect a leak, but it couel be anything. Filter, drain plug, oil cap, dip stick, oil pressure sensor, turbo, etc.

Before you changed the oil, how much oil was in the engine and how often did you have to top it up to keep it full, assuming you did top it up… you may have left it run out of oil for all we know.


“i haven’t changed the oil in over 30,000 miles… i don’t want to get rid of my car because i am in love with it.”

If this is how you maintain a car that you are in love with, I would hate to see how you would maintain a car that you hated!

Because of the extremely long time since the oil was last changed, in addition to oil leaks, I would suspect that there is now an extreme amount of wear on the engine’s bearings and the piston rings as well as severe sludging (which leads to poor lubrication of the valve train), making me wonder how much money should be invested in an 18 year old car with that many miles on the odometer.

You can replace a few gaskets (at a cost ranging from moderate to very expensive), but you could still have an engine that uses a very large amount of oil. It just may not be worth spending any money on the oil leaks, as a result of overall poor maintenance.


It only takes a very small amount of oil to make a lot of smoke when it contacts the exhaust system, this could be a small drip from the cam cover dripping onto the exhaust line, you need to get under there and find it.

Since this started after your oil change, my first port of call would be the drain plug and oil filter to ensure no small leaks are present and blowing onto the exhaust while in motion. It’s possible your oil changers didn’t grease and seat the filter correctly OR more likely they didn’t replace the aluminium crush washer on the drain plug - this is mandatory for Volvo’s unless you want a leak ~ I think the washer is about 50 cents.

As VDC says, you could just ignore it but it won’t get any better without remedial action. If this is anything more than a minor leak you also have the risk of running your engine low on oil during any major journeys. You’ll also be the proud owner of a very messy driveway in a very short time.

On a final note, you could also incur a fixed penalty and civil costs if a cop spots you leaking oil onto a public highway. I’m not a cop, but they are out there, and ever vigilant. If they see that smoke, it will attract further attention.


I believe you when you say 30,000 miles. Kudos for your honesty. The old oil must have looked like clumpy molasses.

And that may be part of your problem. The new oil will be a relatively much lower viscosity and may be getting forced by the lubrication system’s pressure through leaks that the higher viscosity (75% oil: 25% particulates and coked up mess) oil could not penetrate. Thin, soupy concrete mix will “chute” easier and pour into much smaller cavities than high-aggregate mix.

And, since you haven’t been maintaining the lubrication system very well, your PCV valve may be gummed up, enabling the crankcase pressure to build high enough to push the new, lower viscosity oil past worn out seals and gaskets.

Your oil returns from the area around the valvetrains may be pretty gumped up and restricted by now too, exascerbating the problem and possibly allowing oil to be pushed past the long-since compressed valvecover gaskets.

Change the PCV valve. Find the source(s) of the leaks. Use a tracer dye if necessary. Pay particular attention to the main seals at the ends of the crankshaft. And the valvecover gaskets.

If I’m wrong and you meant 3,000 miles, post back.