99 s80 oil consumption

gds · Post by **gds** » 09 Feb 2010, 12:13

I can smell oil burning when the heater is on and the oil dipstick is also smoking. That would seem to be related to the pcv system possibly being stuck but i did a compression test and found a couple of cylinders with low compression. 2 have about 140 while the others read closer to 200 (the car was not warmed up). After squirting some oil in the two weak cyclinders, compression came up. Mileage is 190k miles. I'm wondering if that means the engine needs to be replaced or worse, the car salvaged. It seems to run fine except for the smell and occasionally a hard start.

any advice would be great!

Post by **jblackburn** » 10 Feb 2010, 11:27

Meh. PCV probably needs to be cleaned and that's it. If the car runs ok, the compression may just be low in those cylinders, but not low enough yet to the point where they aren't working. It would make for hard starting in the mornings though.

For now, the compression is doing no harm, and I'd keep driving it as-is. The low compression may be indicative of a head gasket going, or just worn rings. Definitely keep an eye on your coolant level however.

Post by **vegasjetskier** » 10 Feb 2010, 12:15

You can try some Auto Rx to free up the ring packs, assuming they're stuck.

gds · Post by **gds** » 10 Feb 2010, 12:25

do you think a leakdown test would help to pinpoint where the loss of compression is coming from? The car isn't really drivable at the moment (form the oil fumes in the cabin when the heater is on) and needs some other work also so i would like to figure out if it's really worth it before i dig in. There is also some noise coming form the top cover that sounds like clicking. I was wondering if there could be a problem with the valves, possibly the intake valves on the weak cylinders being stuck??

i'm not a mechanic...not sure what you mean by the ring packs being stuck???

thanks!!!!

Post by **vegasjetskier** » 10 Feb 2010, 12:33

Are you sure it's oil and not antifreeze that you're smelling when the heater is on? The heater cores often develop leaks and leak antifreeze into the cabin. You can replace the core yourself.

The clicking is probably either the fuel injectors (soft clicking sound and normal), or the valve lifters (louder clicking sound and abnormal). Auto-Rx may help with the lifters if they're stuck, too. They could also be ticking from low oil pressure.

WRT the ring packs being stuck, if enough sludge builds up between the piston rings and the lands (the area of the piston that the rings slide on), the rings can become stuck and will not create a good seal against the cylinder wall. This results in blowby, low compression, and excessive oil consumption. The Auto-Rx will help to dissolve the sludge and let the rings function normally once again.

gds · Post by **gds** » 10 Feb 2010, 12:42

the clicking noise is louder that the normal clicks that it had when it was new. ONce the oil went low (the first time i noticed this problem) and it was making those clicks even louder, so i assume it's the lifters that i hear.

The smell is of burnt oil and at first was just outside the car, coming from the hood after driving but eventually got the point where it was inside when the heater was turned on. I guess i wouldn't know what the smell of a leaking heater core would be.

I will check out the auto-rx site...sounds like that could be a worthwhile try.

thanks!!!!

gds · Post by **gds** » 10 Feb 2010, 12:43

but the low oil pressure light has never come on.

Post by **vegasjetskier** » 10 Feb 2010, 12:51

Compression tests are normally done with the engine warm. If you can run it, warm up the engine and do the test again, then let us know what the numbers are.

The burnt oil smell could be from a small leak under the hood dripping onto the exhaust pipe. Do you have turbos on your car?

gds · Post by **gds** » 10 Feb 2010, 12:57

no turbos. just the base 2.9.

Post by **jblackburn** » 10 Feb 2010, 12:59

A good wide-open throttle run in 2nd gear, along with the AutoRX can free up stuck valves too if they are indeed stuck.

The heater core leak smells like hot maple syrup, while burnt oil smells kinda like...burnt bacon.