Smoker "Valve Guide Rubber"?????

[pdudley11]

93 Q45 242,000 miles. Car smokes after been idling for about a minute when accelerator is mashed on. Tune up about a month ago, and no oil or any liquid on spark plugs...Nissan mechanic who owns his own shop now said maybe "valve guide rubber" ??? First of all, what the hell is a valve guide rubber (official terminology) and could that be the problem, if not what else could cause the car to be burning oil?

[maxnix]

Oooops! Wrong technician. He just told you he doesn't know squat from shinola.

Valve guide wear maybe if it is blue smoke.

Guess the timing chain guides have been replaced.

[pdudley11]

no, the timing chain guides have not been replaced, not since i've owned the car. Would that cause this problem?

[maxnix]

Probably not, but it could be fatal to the engine, and even you in the wrong circumstance.

Go read an Article or two from the sticky above.
Modified by maxnix at 11:13 AM 5/17/2008

[pdudley11]

wheres the sticky that your refer to and what else would cause the car to burn oil

[qship96]

Motor is burning oil due to worn piston rings or valve guides/stem seals-at 15 yearsand 242,000 miles it is old and tired, not unlike a 90 year old person. This is a long, long life for anything but a overmaintained engine from BRAND NEW using premium synthetic oils changed frequently and operated in a manner that extends longevity{proper warmups,using factory air filters, not K&n type,no overheats,etc etc}

[maxnix]

wheres the sticky that your refer to .....

Right above all these posts.

[pdudley11]

So basically, qship96, you're saying its time to invest in a new car?? The value on this car is about $1815 in fair condition, I'm sure a repair like that which sounds pricey, will cost almost half of the value of the car. Does is really make sense to fix?

[qship96]

The motor would need to be torn down and rebuilt to correct the problem, which would cost thousands to do somewhat correctly. I would switch to a thicker oil to slow down the burning issue and just drive it. If the motor still feels powerful and the oil is replenished as it burns {check oil level weekly and add as necessary} you could get tens of thousands more miles out of it. When it starts blowing clouds of smoke full time as you are traveling down the road, its time to junk the car and find another.

[oldmako]

Bingo.

[goody90q45]

no, the timing chain guides have not been replaced, not since i've owned the car. Would that cause this problem?

We are tallking about black smoke (oil) not white smoke (injector leak) correct?

[Q451990]

93 Q45 242,000 miles. Car smokes after been idling for about a minute when accelerator is mashed on. Tune up about a month ago, and no oil or any liquid on spark plugs...Nissan mechanic who owns his own shop now said maybe "valve guide rubber" ??? First of all, what the hell is a valve guide rubber (official terminology) and could that be the problem, if not what else could cause the car to be burning oil?

How much oil is it using/1000 miles? I think I would just keep it topped off and live with it. When it gets too bad to bear and you see the people driving behind you choking - maybe think about a JDM engine swap if the body and interior are in good shape.

I don't think I would invest in timing chain guides for a smoker with that many miles.

To answer your question, your mechanic is talking about your valve stem seals... as other posters said, your smoke is coming either from leaking valve stem seals, or leaking oil rings. Neither are easy to fix or worthwhile vs. swapping in a JDM (Japanese Domestic Market) take-out engine.

Heath

[Q45denver]

Valve seals are viton rubber and not known to be a problem area however anything will wear givven enough time. Might be worthwhile to try some BG Quick Clean for engines and change oil. Sometimes the valve stems get gummed up with varnish and pervent a proper seal. The BG suspends the varnish but must be drained hot. You could also do a cylinder leak down test to determine the source of the leak.

[pdudley11]

When I first noticed that the oil was burning, I didnt refill the tank until about three weeks later when the valves could be heard tapping. I filled it with a gallon jug 5W-30. I think possibly there is a small leak on the valve cover gasket as well, because there is a small drip after the car sits for a couple of days. but if i put a gallon of oil in the car and drive it no more than to work and back everyday, in about three weeks time the valves can be heard tapping! I've also noticed that when the car is parked and running, just idling, the smoke is blue, but after sitting idling for about a minute or two and i drive off the smoke is white, but the not the kind that results from a cracked head, just white smoke. what would that mean?

[goody90q45]

We are talking about black smoke (oil) not white smoke (injector leak) correct?

........I've also noticed that when the car is parked and running, just idling, the smoke is blue, but after sitting idling for about a minute or two and i drive off the smoke is white, but the not the kind that results from a cracked head, just white smoke. what would that mean?

The white smoke, since you didn't mention your engine oil being creamy color (head gasket), could well be from a leaky fuel injector lower o-ring. The blue smoke at start up could be oil blow-by from the cylinder wall being washed with fuel from the leaky oring.

Your engine has only 242k on it and should be good for another 50-100k miles. As other posters have said, it's time to do at least a compression test on the cold engine to find the suspect cylinder(s), or a power balance test with a consult program, or a fuel pressure bleed down test. Don't give up on your engine quite yet.

How much oil are you burning (if any)? Is the CEL Light staying on? Pulled ECU codes?

[pdudley11]

The check engine light is not on, has never been on. I definately will look into getting a compression test done and changing all the lower-o rings on the injectors. THANKS A LOT PEOPLE!!

[ScottJackson]

Hold up, you say you run it until it's low enough on oil that it loses pressure to the point the valves are ticking? Rod and main bearings don't actually need much oil to survive as far as lubrication goes, but there needs to be oil pumped to them in order to lube the cylinder walls and also any oil flow to the top of the engine will quiet the valves/followers unless there's something screwed up in that area. I'd say that engine is becoming toast in very short order. By the way, too much fuel is normally a dark grey or black smoke, burning oil is a light bluish smoke, and pure white is coolant.

[Q451990]

When I first noticed that the oil was burning, I didnt refill the tank until about three weeks later when the valves could be heard tapping. I filled it with a gallon jug 5W-30. I think possibly there is a small leak on the valve cover gasket as well, because there is a small drip after the car sits for a couple of days. but if i put a gallon of oil in the car and drive it no more than to work and back everyday, in about three weeks time the valves can be heard tapping! I've also noticed that when the car is parked and running, just idling, the smoke is blue, but after sitting idling for about a minute or two and i drive off the smoke is white, but the not the kind that results from a cracked head, just white smoke. what would that mean?

You refilled it with a gallon? As in four quarts? That's really low for a 6 quart oil capicity engine! Did you check it with the dipstick to make sure you didn't overfill it? The oil level should be maintained between the upper and lower mark on the dipstick, which is the difference of one quart. You might want to track how many miles it takes to go from six quarts to five (top mark to bottom mark) to help evaluate how much oil you're using. I agree with Scott, if we're really talking about oil consumption in terms of gallons and not quarts between oil change intervals - this engine is seeing it's last days.

Heath

[qship96]

Sounds like it could be a fun car to enter in your local demolition derby if it is really going through 4+ quarts of oil in 3 weeks- enter it and give it a proper funeral while destroying as many other vehicles as possible in the derby!

[maxnix]

Sounds like it could be a fun car to enter in your local demolition derby!

At least chain guide failure won't cause any loss of life to any innocents.

And it's only worth what......$1,815? Only fair (generously speaking)condition?

Better it die in faux combat than on the side of the road.

[Haitian_King]

At least chain guide failure won't cause any loss of life to any innocents.

And it's only worth what......$1,815? Only fair (generously speaking)condition?

Better it die in faux combat than on the side of the road.

Perhaps the guides have been replaced in the 242k miles? Maybe just not by the CO. From what I've read on the guide issue, having a VH45DE with the old-style guides at such a high level of mileage would be quite a sight to behold, n'est-ce pas?

Maybe the CO was fortunate enough to have been the recipient of one of the fabled 93's with metal backed guides from the factory.

I didn't see anywhere that the CO has said that the 242k miles were all his.

[Q45tech]

"And it's only worth what......$1,815?"Once a car is 15 years old it is not about resale price but about the $2,500-3,000 per year it costs to drive plus gasoline and insurance.