Smell burnt exhaust gas in the car

cpozzer · Post by **cpozzer** » 21 Oct 2007, 05:20

hi guys,

ive gotta strange problem,its been a couple of months now that when im at a traffic light or standing on idle with my blower on i can smell exhuast gas comming out from the blower system,when i start driving the stink of gas doenst come in anymore.

about 4 months ago i had some work done on the car and after this the problem came up,before i never had this gas stink problems.
what i did to the car is that i installed a new turbo and had the pcv system cleaned out.

another thing that i noticed is that at night when i get back home after a half an hour drive i notice in front of my headlights smoke comming out of the engine (only at night with headlights on and car on idle,in day time you cant see it)

help is apreciated

Thanks Claudio

p.s could it be the engine that has old oil on it (the old turbo was leaking) and when the car is on is burns it?

Post by **MadeInJapan** » 21 Oct 2007, 17:06

Two places to check (I suspect it's burning oil and not gas).
1. Top of the engine under the plug cover
2. Under the car- turbo return line.

If it's #1, look for the PCV return line on top of the car...is it on tight? Or the oil filler cap gasket is leaking. If it's #2 then there is a kit you can buy with the o-ring and gasket to fix that. Either way, oil can drip onto the exhaust (fire hazard so you should fix it soon) and if you're sitting still it will come into the cabin via the air ducts.

cpozzer · Post by **cpozzer** » 21 Oct 2007, 22:55

ok!thanks for your reply!ill check it out soon

Claudio

turbotim2 · Post by **turbotim2** » 24 Oct 2007, 10:35

It should have burned any old oil off from it by now. You may have an exhaust leak from the turbo replacement. Check all of the connections in the exhaust system.

cpozzer · Post by **cpozzer** » 25 Oct 2007, 11:39

thats what i also think...there is a leak somewhere

PaulV70 · Post by **PaulV70** » 15 Dec 2007, 07:40

Hi,

I have the exact same problem. This smell of oil inside the car. Its got much worse lately, slightly worried its bad to be breathing in.

It started about a year ago, when volvo did a service. I took it back, but they were not able to locate the source of the smell, and tried to deney it existed.

What is the PCV? And the PCV return line? Also where can i find this to see if its leaking oil? (the car is a 1998 Volvo V70 2.5 turbo). Is it a common problem or easy fix?

Any help hugely appreciated, sorry to hi-jack the thread but it sounds like the exact same problem.

Thanks,

Paul

Post by **MadeInJapan** » 15 Dec 2007, 08:18

The PCV system is actually more than one thing...it is the series of small vacuum hoses that run from the bottom of the air-intake (accordion hose) from the air filter to the turbo (or if a non-turbo car, to the throttle body) to a black, plastic oil separator that is under the intake manifold, back up to the top of the engine. If any of these hoses or the oil separator gets blocked, then positive pressure builds up in the engine and one of the seals springs a leak, and or, the oil filler cap gasket will leak. The leaking oil sometimes finds its way to the exhaust manifold, thus you smell burning oil in the cabin. Not to mention a clogged PCV can (and usually does over time) lead to the rear main engine seal leaking- which is very expensive to fix because the engine and transmission have to be separated to get to the seal. The fix is a little taxing- about 5 hours of labor for the first timer....main reason is that the intake manifold has to come off to get to the oil separator. www.fcpgroton.com sells a kit to replace the PCV system. It's best to do this than try to clean everything. The reason is because after years and many thousands of heat-cool cycles, the rubber hoses are usually brittle and the oil separator (or breather box ) is gunked up. If you buy the kit, make sure to also get a intake manifold gasket and a throttle body gasket (you might as well clean the later while you have everything off).

To test to see if your PCV is kapput, with the engine idling, take the oil filler cap off and place the palm of your hand over the opening...there should be a slight sucking sensation, and no pressure outwards towards your hand. Also, you can pull your oil dipstick to see if there's suction there as well. If you turn your car off and smoke pours out of your oil filler dipstick tube, that's another sign.

Volvo recommends an inspection of the PCV system and cleaning of the "pcv nipple" if needed every 60K miles (the nipple is where the PCV hose attaches at the base of the accordion hose with a bayonet connector) but they make no big deal out of this and often "forget" to do this service. We who have owned these cars for awhile realized awhile back that if the PCV service is not done and replacement of the entire system (usually at or before 100K miles) then we typically suffer blown engine seals and expensive repair bills.

A couple of vacuum hose diagrams (including the pcv) are located in the repair database as a reference. Conversely, there is a sticker under the hood of your car with your car's specific diagram. It is hard to see, so it's best to take a digital picture of it and then view it on your computer screen.

The PCV replacement procedure itself is outlined (with pictures) in either our repair database or over at the www.volvospeed.com forum (you'll have to do a search)..

Good luck and I hope I've outlined the PCV system and may have answered other questions you have about this.

PaulV70 · Post by **PaulV70** » 15 Dec 2007, 16:02

Hi,

Thanks very much for the response. I just went outside and did the check on the oil filler with the palm of my hand, and there appears to be a slightly outward breeze (positive pressure in the engine). Does this mean i should clean out my PCV system? If so i will dismantle it in the morning.

There is a very strong smell of oil when the bonnet is open.

Should i be looking for any leaks of oil from the PCV system? Im guessing i should only find air in the PCV system?!

Thanks again,

Paul

Post by **MadeInJapan** » 15 Dec 2007, 18:26

Yes, you should clean, and actually probably replace the PCV system, but it's not something you can just "do" in the morning. It will take time and planning and having the right parts. There should be a vacuum in the PCV lines under normal idle, but as the car boosts (turbo, if you have one) the air in there will actually flow the other way....some call the PCV system a "breather" system because it does just that....it breaths back and forth. The oil in the lines is from exhaust condensation in the PCV system. If it is clogged you get more in there than you wish and it can start smelling. That said, the turbo lines and the vacuum lines are somewhat related too via the PCV nipple at the base of the accordion pipe. When that or any of the PCV system gets clogged you'll get more oil in the turbo hoses as well. The lowest part of this (right angle hose at base of radiator on driver's side) tends to accumulate oil. Even with a "breathing" pcv system in my car, I tend to take that 90degree hose off and clean it out every-other oil change. Hope this helps.

Paul-93-850 · Post by **Paul-93-850** » 27 Jan 2008, 01:58

I was smelling oil in the passenger compartment because the oil trap coupling was broken. It's a two inch rubber part between the oil trap and the hose leading to the flame trap. Everyone told me that I had to remove the manifold and replace the whole series of parts since I'd be doing an all day job and I'd would have the manifold off. Screw them. I just took a really long screwdriver and pried off the broken coupler from the nipple on the top of the oil trap. I disconnected the hose on the other end, pulled it out, and put the new coupler on. Putting it back on required that I push it on to the nipple with the same long screwdriver. It was a royal pain in the ass but better than removing a manifold. It's staying on fine without a clamp.