2002 SE Automatic valve seals are bad and the car is smoking horribly on start up. Mechanic says its just a matter of time before the engine goes. He says to buy a new motor. Any suggestions on where to get a motor or has anyone encountered this problem before?

 

You can do valve seals with the motor in the car, and without pulling the heads off. You just need to have the proper tools to do this. I've done a few of these on the Camry V6s. You need to compress the combustion chamber with air, and keep it sealed whole time at TDC compression, then you need a special impact keeper removal tool, once thats out you can take the spring off and then slide the valve seal off the stem. Its very doable.

 

The mechanic suggested replacing the entire engine because if you replace the valve seal then something could be damaged in the lower end

 

Talk to a different mechanic! Why would you replace the entire engine over valve seals? Get a leak down test done to determine how extensive the damage is and go from there, good luck.

 

Has anyone else on here had issues with the valve seals going bad? With the seals being bad does that hurt anything else in the engine?

 

How many miles on the car? Rare for a Maxi. Anything done to the car recently? Spark plugs all torqued and no oil in the spark plug tubes? Every start? Does it puff smoke when you accelerate after a long idle as well and/or when you hit the throttle after a long downhill "coast" at highway speeds? Is the performance and oil consumption normal? Pull the plugs and check for obvious signs of oil on the plugs..........probably one cylinder. Like the guys above have said, don't pull the engine until you do a cylinder leakdown check. If the cylinder leakdown check is good then do the seals change per BlackBIRDVQ above. And a really dumb question........ you haven't been parked in an extreme nose up and low right side attitude when this happens?

 

I've not had that problem but I doubt you'd need a new motor. However, I would recommend a second opinion...maybe from Nissan. But if the valve seals are the deal, you may want to check with Toga and see if they carry any VQ35DE seals.

 

Because it is cheaper to buy and install a junkyard VQ than it is to repair internal damages.

But bad valve seals on something like this is VERY rare. Has this car been overheated and grossly over run on oil changes?

 

I also have doubts that all valve seals are gone unless something very bad was done to the engine as the guys mentioned. If you have not done anything bad to it (overheat, oil changes, plugs, etc) you can most likely find that only one cylinder is causing this problem. To find which one look at the spark plugs and if you find one that has more burnt crap on it than others that would be the one, and once you remove the valve covers you can tell which valve is leaking. I've seen it once on a newer engine where an intake valve's seal was warped (probably mfg defect) and caused oil leakage into cylinder... And just change those seals for a few $$ and you'll be good to go... Get a second opinion before you throw away a few thounds on engine replacement...

 

Even though it's a 2002, what is the mileage? Seals may be worn if the mileage is high. Get a sompression test done to confirm valves, rings and head gaskets are ok before even considering a new motor. It wouldn't hurt to get an oil pressure test done also.

 

the milage is 80k. Its my moms car and they are going to rebuild the head instead of a new motor. She got a second opinion and it was determined that a new motor was not necissary. Thanks for the replys guys!!!

 

I am now burning oil and I suspect that I too now have this problem with the bad valve seals. I will be doing compression tests and possibly leak down tests in the near term. Would any of you know how difficult the job is to do on the VQ35DE engine? The ESM shows that the whole front of the engine has to be disassembled - timing chains, etc.

Thanks in advance.

 

To get at the seals you have to remove the cams. That requires removing the cam brackets which in turn requires that you remove the timing covers. Lotsa work.

 

It is not difficult. I'm not a mechanic and I did with my brother on a 280Z. It wasn't that difficult. We did it in like 6 hrs with all the required tools BUT not compressing the chamber

 

wow this is a rare thing. only 80k and the valve seals are bad. that vq was abused in some sort of way.

 

Actually, I have taken very good care of my car, using Mobil 1 and frequent oil changes. Lots of 3.5VQ engines are burning oil. If you don't believe me go check out the 350z forums, Altima forums and G35 forums and you will see what I mean.

It may be that Nissan used cheap seals which are failing. The problem is that these appear to be hard to get to and repair.

 

that is wy if i ever own a 350z, i swap a vq30dett in there. i am glad that my vq doesnt burn oil. knock on wood.

 

Thank God you'll never own one.

 

and why is that?i can pick up a z from a auction for way cheaper then buying a new one. yeah it will have some damage done to it but it doesnt bother me.

 

LOL DOUCHE LOL


oh sorry... erm. yea, the procedure is pretty easy, more time consuming than difficult. a few different tools that can be used that compress the valve spring while the heads are installed on the vehicle.

abuse wouldnt decrease the life of a valve seal, as long as the engine were kept within normal operating conditions (operating temp, oil condition, etc)

 

and if it werent kept in those condition it would mean it was abused.

 

I'm not endorsing just chucking the engine, but if your VQ is exhibiting THESE symptoms, then that motor HAS BEEN abused.
This sort of thing on a VQ is unheard of with relatively low miles, or high miles for that matter, if it's been properly serviced and maintained.
Somethings wrong there.
gr

 

There aaren't too many people in here that abuse theirs more than I abuse mine and mine burns little oil.

 

I abuse my engine alot more than probably 90% of the .org here, and I don't have any valve seal issues.

People need to- do a leak down test to see WTF is leaking on their engine, and NOT make all kinds of weird assumptions- oh its my cats, its my rings, its PCV system, or bad valve seals. Once eliminate everything by doing a cylinder leak down test and don't see any notable problems with the engine- you can assume that eighter valve seals are leaking, head gasket is leaking- internally.

There are like 3 or 4 threads open bout the oil consumption problems here on the forum, and no one seems to know where its going. Take some initiative and figure out where its coming from. People from half way across the globe can't diagnose your oil consumption problems, you need to ! *** Nissan, technicians at Nissan are PARTS repleacement semi-skill, they are NOWHERE even close to being a PROFESSIONAL mechanic. Do your own diagnosis- or have a GOOD mechanic look at it for ya, bring Nissan the results, call up 800 Nissan Blows and demand a new engine.

 

how does an engine overheating due to a mechanical failure not in control of the operator of the vehicle constitute abuse?

and oil condition is lack of maintenance, not so much abuse.

good try though.

 

unheard of for a 'high' mileage VQ?! why are there so many threads on oil consumption, and references to 350z, Gs and other VQ35 platforms with oil issues.

granted its a small percentage, but its certainly not 'unheard of'

you! you there on that high horse! come down here!!

 

quoted for truth.

THANK you!

though a head gasket would probably be noticable, and get worse quickly and a leakdown wont point to a leaking valve seal.


LOL... good post 10/10

 

when a engine is abused it is the operators fault because he is in control and he is the one that is putting stress on the mechanincal parts of the eninge and that is why they fail sooner then they are supposed to fail. i mean i understand when parts fail because of defect and that is not because of the operator but the chance of that happening is increased when the engine is abused and that all rides on the operator. and i see lack of maintanance as abuse to the engine.

 

'abuse' is deliberate, lack of maintenance usually isnt.

but were arguing over the meaning of a word. so im dropping the tomato tomah-to thing, you havent explained how its the operators fault for a thermostat not opening and overheating the engine, or a radiator cap failing and causing boilover.


plain and simple, beating on the engine, clutch drops, high RPM, WOT, will NOT increase wear on the valve seals, unless of course, you can prove me otherwise.

 

I agree that valve seals are not going to show bad durring a leak down test- but piston rings, burned valves, or blown head gasket will show.

My 94 Q45 has had severely warped cylinder heads and it burned coolant at a pretty alarming rate- YET there was no white smoke out the tail pipe, and it did not mix with the oil. So head gasket leaking oil slowly might not show any tail pipe signs...

I did note on a few VQ35s that I seen start up in the past that they do exibit a bit of blueish smoke at start up when cold. Which means most likely leaking valve seals.

Since most of the VQ35s are fairly new engines, thermostats sticking on them is a very unlikely scenario. Reasons thermostats stick are due to neglible maintenance- aka coolant not being repleaced and rust forming on the coolant galleys, water pump and thermostat. FYI I change my coolant once a year on all my cars since it don't cost me a thing to do, and I add a bottle of Redline WaterWetter along with it.

Toyota has alot of valve seal problems on their V6 engines, some start to leak at even 50K miles, and some last over 200K miles. I had a customer that had a 98 Sienna with only 70K miles which needed valve seals pretty bad, technically the engine was in need of an overhaul or replacement. I've done valve seals on V6 Camrys with the heads installed on the engine- but with the amount of work needed to do these on a VQ I would just pull the heads off, it would probably take another 30 min worth of work to do that.

 

That's an universal understanding "abuse" is anything that contributes adverse effect to the car, which bejonds normal wear and tears. Improper maintenance, lack of maintenance, deliberate abuse are all falling into the same category.

 

BBVQ, call it a cooling fan failure, open ckt, relay issue... anything. i was just using the tstat as an example. just because an engine overheats doesnt mean the customer is automatically at fault, nor is it a case of abuse. just trying to make a point. abuse will not cause valve seal failure.

'abuse' *is* deliberate. every definition of the word is active, its an issue of deliberation. abuse isnt associated with ignorance or lack of action. in every case, its an act of knowing and willful mistreatment.

'sexual abuse' is not defined as your wife refusing to have intercourse with you.

need i move on to alcohol abuse, drug abuse, spousal abuse, child abuse... vehicular abuse...