VG33 over heated question

[ahardb0dy]

So, my neighbor just e-mailed me saying the engine in his xterra over heated and stalled, do not know which happened first. Of course this is a PF forum but since the PF also uses this engine I thought I would ask here.

 

I am waiting to hear back from him on whether the engine runs or not so, if it did overheat what is involved in repairing it? Is it that the heads would warp? Can they be shaven down slightly and re-installed? Should he pickup new/used heads? Or possibly get a used engine?

 

Thanks

 

Almost forgot, he took it to a shop and they said it has "burnt heads" What ever the hell that means??? They quoted him $3K to fix it. I told him he could do it himself with help from the guys on the forum.

Edited October 9, 2012 by ahardb0dy

[Alkorahil]

Almost forgot, he took it to a shop and they said it has "burnt heads" What ever the hell that means??? They quoted him $3K to fix it. I told him he could do it himself with help from the guys on the forum.

 

 

Gee-himiney! Did he just keep going and going till it gave up the ghost?

IMHO based on what the mechanic is saying your neighbor needs to get a low milege engine from a salvage yard. He could have sleave,bearing or piston damage too.

 

What the mechanic is talking about is 'burned valves'. A "burned valve" is a valve that has overheated and lost its ability to hold a leak-free seal. Valve burning is usually limited to exhaust valves because they run much hotter than intake valves.

The diagnosis of a burned valve is usually the result of a compression test. If a cylinder shows little or no compression, it frequently means the exhaust valve is not sealing. The valve may or may not be actually burnt (melted), but have other physical damage such as warps, cracks or areas where pieces of metal are missing or eroded away from the valve face.

To fix this you need to remove the cylinder head, replace the bad valve(s) and reface (or replace) the valve seat. As a rule, the head is usually given a complete valve job at the same time because the rest of the valves and guides probably need attention, too. If one exhaust valve has failed, the rest are probably on the verge of failure if they haven't already started to leak. I would be very suprised if it was just one valve only that was bad.

 

A complete valve job parts + labor or if the heads are to badly warped; two new heads + labor (and assuming the rest of the block isnt damaged after they put it back together) will be as much if not more as just getting a good low milege motor from a salvage yard. Many reputable places offer warranties or some form, usually 6 months or even a year.

Companies such as LKQ offer rebuilt/reconditioned motors with up to lifetime warranties and they deliver and at (IMHO) reasonable prices.

I also very much hope it wasnt a supercharged Xterra!

Edited October 9, 2012 by Alkorahil

[ahardb0dy]

Thanks for the detailed reply, No it's not a supercharged x, it was the one i posted pics of a while back with the ARB's and the ARB winch bumper, here's a pic to refresh your memory:

 

 

I'll have to contact the place where I bought my JDM engine from to see if they have any VG33's for him.

[Tungsten]

I am wondering if the ECU on the X has some sort of a protection system built in. This being Nissan and all they may actually have programmed the ECU to have the engine shut down before any serious damage was done.

[ahardb0dy]

Ok so need some feedback on new details I just got from my neighbor, want to see what you guys think.

 

Just spoke to my neighbor, he said the truck was running hot in traffic or when sitting, (most likely is the fan clutch)

he said the truck sometimes had water spots under it and he had to keep adding water to it, he was driving it home one day and said he heard noise from the engine, he thought it was in the bottom end and he stopped at a gas station he said steam was coming out from under the hood, he said he waited a while to let it cool than the battery died so he jumped it from the second battery in the truck and added water to it. He continued to drive home and the gauge was pegged and it stalled when he stopped at a traffic light. ( I know NOT GOOD)

 

He got it running and there was water pissing out of one of the heater hoses so he had it towed to a shop he deals with, they got it running but it is very noisy.

 

I spoke to my mechanic about this and he said he would fix it for $450 plus any parts and if he needs to send the heads to machine shop he deals with what ever they may charge, what do you think is making the noise and what else besides the fan clutch and the leaking hose may need to be replaced? I already suggested doing the timing belt while it is apart.

 

Thanks

 

Also, called the place I bought my JDM engine from and they said they have one VG33 in stock for $799

Edited October 31, 2012 by ahardb0dy

[Trogdor636]

I had a water pump go out once upon a time, made a horrible noise.

[Alkorahil]

I had a water pump go out once upon a time, made a horrible noise.

 

Agreed. Sometimes when the bearings go out on a water pump it can make some very horrbile noises.

It basically wants to seize up but the motor is forcing it to still turn.

I have seen bearings smoking and belts smoking from this.

 

 

Overheating will likely harm the thermostat since it just got cooked. I would replace it and any other coolant hoses that feel 'thin' Make sure the radaiator cap still holds pressure too if the radiator boiled over.

[ahardb0dy]

Well my neighbors xterra finally made it's way to my buddies shop, will find out in next couple of days what exactly it needs to survive. I told my neighbor I highly would recommend having the timing belt and knock sensor replaced while it was apart. He said he would ask fort hose things to be done once he finds out what was wrong with it.

[ahardb0dy]

So today I called my mechanic buddy who is repairing my neighbors xterra, he told me the engine got so hot that it melted the plastic on the knock sensor and the plug and also melted the 3 long spark plug wires. He said he had to chisel the rubber residue out of the holes to get the plug wire boots out ! I know he sent the heads out but do not know if they were shaved or rebuilt, will find out after Monday. He told me all he had left to do was tighten the alt belt and add coolant and he will be done with it.

 

Will have to wait until my neighbor picks up the truck to see what the final damage was ($'s)

[devonianwalk]

Holy crap! How can an engine still be good after that? I mean, melting external wiring and all?

[ahardb0dy]

Will see after he finishes doing what ever he has too, I'm sure my guy won't say it's done if it still has issues.

[ahardb0dy]

Truck is done, shaved the heads, new head gaskets, intake, valve cover gaskets. New knock sensor and plug, new plugs, new wires, couple of hoses, new oil, new antifreeze, water pump, timing belt, think he said it needs the O2 sensors replaced and the IACV, $450 labor, $80 to shave the heads, $600 in parts, total was just over $1100

[Kyle94]

how can the engine still have compression after all that?

 

so its running now? :O

[ahardb0dy]

yes

[Tungsten]

Theoretically it should have slightly more compression after shaving the heads. I don't know how much was shaved but that can impact the timing too.

[96Pathfinder4x4]

Tell your buddy: In any overheating situation, to pull over.

If you can't fix the problem, have it towed. A $200 towing bill is better than a $1100 engine rebuild....anyday.

[ahardb0dy]

My poor neighbor, he just got his xterra back and now the tranny went !! so it's being rebuilt along with a trans cooler and mild shift kit

[rocky2]

Tell him to sell it and buy an R50 Pathfinder

[ahardb0dy]

I told him it should almost be like new now with the engine repaired and tranny rebuilt.

 

Friends don't let friends buy CAR50's !! :laugh:

Edited December 23, 2012 by ahardb0dy

[rocky2]

Touche'

 

But he'll have to get another 1st aid kit and attach it to the rear next to the fake side step.

Edited December 23, 2012 by rocky2

[ahardb0dy]

Or he can mount the first aid kit on the front or Rear ARB bumpers.

 

The truck is too nice to get rid of, if he though of selling it I would have to find a way to buy it, as I said front and rear ARB bumpers, front and rear ARB air lockers, air tanks under the front fenders (2) and the side steps were made into air tanks as well, dual batteries, Cal Mini HD steering, lot's of goodies.