Collapsed Lifter, What To Do?

[Trainman]

The background to this is here: NPORA Topic Link

 

 

After several trips to the dealer, this is the final diagnosis: One of the lifters for the right rear cylinder has collapsed and is showing over 30 thou clearance (the largest gauge they have is 30 and it does not contact the cam or lifter).

 

The dealer says the cam shaft has to be removed to get at the lifter. This is a 14-16 hour procedure, plus the 3 hours already into it.

 

The dealer also says that there is no harm in running the engine as is, just have to live with the ticking noise. As it is a 4 valve head, they do not see any issues around power or fuel consumption. They suggest just leaving as is.

 

Any thoughts? Would Nissan (or any motor manufacture for that matter) actually design a valve train that can be adjusted that would take so much labour to do? I guess I am thinking back to the "old" days when valve adjustments were more common, like my '69 510

 

OK to leave as is or should it get fixed?

 

Thanks, Tman

[jj big shoe]

A bike shop would charge 2hrs labor to do a valve adjustment on my old Honda I-4 CBR 900RR at every 16,000 miles. To do one on a V-twin Ducati with their "desmodrive" valvetrain would take over 20hrs labor, go figure.

[02silverpathy]

I would first drain a some oil (1 qt) and add a quart of ATF run the engine for a few mnutes---(listen for noise to go away??) then drain and change the oil & filter...whatever gunk has built up will now be in the filter. If the atf does not clean out enough stuff to quite that ticking then its not just a sticky lifter.

 

A buddy and I did this to a Caddy Deville with 273 on the clock...pretty neat! Unfort, it also had a head gasket leak, so noises went down but the head gasket was another story!

[Trainman]

The lifter is not stuck, it is damaged. The dealer had the valve cover off and actually looked at it and measured the clearance at over 0.030". It is supposed to be between 0.010 and 0.015" depending on if it is intake or exhaust.

 

Best way to describe the system is this: the lifter is an upside down bucket shape with a bit of a knob or nipple on the top. It sits on top of the valve stem and the knob/nipple part rides directly on the cam shaft lobe. Older style VQs had shims for valve adjustments but the newer post August 2001 build date have these buckets. The only way to adjust the clearance is to replace the lifter with one of an appropriate thickness. But because the lifter rides on the cam shaft, the cam shaft must be removed to get the lifter out.

 

To remove the cam shaft, the timing chain has to come off. To get the timing chain off, the oil pan and the chain cover have to come off. This requires the motor be removed from the truck. I have the factory service manual and have read the procedure. The 14 hrs noted is the book time just to replace the timing chain let alone start taking cam shafts out.

 

Trust me, the dealer has tried every chemical/solvent/lubricant they know of to try and fix it but it is so far gone that it needs to be replaced. They think the knob/nipple has broken off.

 

Thanks for your suggestions anyway.

[02silverpathy]

Any clue how this could have happened?

 

This is rather upsetting, it sounds as if the valve train is a "throw-away"...I had a mech, whom I do not like, go on and on about how all nissans are junk waiting to blow...so hearing that there is NO valve adjustment sounds as if once it is broken you just pitch it and get new.

[Trainman]

Any clue how this could have happened?

 

This is rather upsetting, it sounds as if the valve train is a "throw-away"...I had a mech, whom I do not like, go on and on about how all nissans are junk waiting to blow...so hearing that there is NO valve adjustment sounds as if once it is broken you just pitch it and get new.

 

You can adjust the vales, it just such a hassle. You do the adjustment by replacing the bucket valve lifters. Nissan offers them in different sizes/thicknesses to do the adjustment. The FSM describes what needs to be done and the dealer confirmed the instructions. Note this is only for post-August 2001 build dates, if you are lucky enough to have a pre-August 2001 motor, it uses easily adjustable shims with no need to remove the cam shafts.

 

And I have no clue how this happened. I change the oil and filter every 5,000 km/3,000 miles and am running full synthetic. The dealer says everything up top is nice and clean; they are just as puzzled by this as I am.

[02silverpathy]

Thanks for keeping me straight...and your updates are priceless! Have you called Nissan NA to get/give info on the problem?

[Trainman]

Thanks for keeping me straight...and your updates are priceless! Have you called Nissan NA to get/give info on the problem?

 

Good thought, I will do that

[nissandoms47]

So how much is the dealer wanting to charge you? It might be cheaper just to replace the engine yourself..

[Trainman]

So how much is the dealer wanting to charge you? It might be cheaper just to replace the engine yourself..

 

They estimated around $2,500.

 

I am just going to live with a bit of ticking as it is not affecting drivability at this point. My main concern was that there was something much worse that had to be fixed.

 

I was rally hoping some Nissan guru would come on and say "Ha!, you do not have to remove the cam shaft, just undo the bolts holding it in and tip it up enough to get the old lifter out and the new one in". Oh well..........

[02silverpathy]

I don't know why that wouldn't work....I mean as ghetto as it sounds why wouldn't a shop vac with a piece of cheese cloth (to kep oil and small pieces from being siphoned)over the end work?? Or even a hand pump, like for brake line flushing, with a suction cup end on it work?

 

Ok, now you have single handedly taught several of us about the lifter style found in post 8/01...so what was in -8/01 ? Turns out my girl is an 06/02, I would think that 8/01 covers all the 2002 models. I spent some time looking at the "bucket" style lifter...pretty neat, does look fairly fail proof other than general wear that everything is suseptable to. Reason of design, less metal and less expensive.

 

TMan...what on eath is in the first run VQ pathy's??

Edited April 17, 2008 by 02silverpathy

[Trainman]

TMan...what on eath is in the first run VQ pathy's??

 

They use shims. And some 02s must have them as my FSM makes a reference to them and how to do the adjustments. Real easy......well compared to the bucket style anyway, no need to remove the cam shaft(s).