hey i have a 2004 xtrail , engine type qr20 4wd ,the problem is this the head gasket fail about a month ago ,i sen t it in and pressure tested the head for cracks and so on ,had to shave the head cause it was warped a bit ....no cracks !!!! used the original head gasket bought it from the motorist ,low and behold the head gasket went bad again three weeks after ,has anyone had a similar problem ,any experiences like this with the xtrails ?????
your input would be greatly appreciated !!!!

Buy some aftermarket head studs and torque it high.....problem will be fixed

ok cool ill mention that to my mechanic ,anyone else with any suggestions ,trying not to go down the buying a new engine ,they kinda hard to get and very expensive !!!!

and the reasoning behind this is what again?

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resurface the block, with cast iron blocks you usually dont have a issue but aluminum blocks will warp just like the head and metal gaskets need to have precisely mating surfaces, you can get away with a small amount of warp using composite gaskets but not metal headgaskets

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thanks

also, I have not heard this being a problem with the nissans but it has happened with the toyota camrys etc, on over heating the threads in the block become weak and fail, this will cause the head bolts and studs to loose tension hence the head gasket will not seal. This problem will be obvious to the mech though by bits of aluminum in the head bolt threads and/or difficulty in removing tightening the head bolts. The fix for that is to helcoil the block threads or have studs remade with a larger thread diameter.

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"upon seeing the shadow of a pigeon, one must resist the urge to look up" - Confucius

Had this problem before.
The QR20 uses torque to yeild bolts and have specific torque regimen.
Also it may be necessary to deck the engine block in addition to shaving the head.
All of the head bolts have to be checked for stretch and replaced if necessary.
I will post the nissan specs.

as a xtrail owner, i eventually did an engine conversion after 3 gasket and 1 complete engine replacement, I think when gasket goes cylinder sleeve in block is also damaged #justsaying Good Luck

Exactly, that is why you may have to machine the deck surface of the engine block in addition to the cylinder head.

Here are the torque specs and the instructions on how to inspect the cylinder head bolts for the Xtrail.

converted to? sr?

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ok guys so i got the head and block shaved , its about two weeks now and every things seems to be working fine , water level is still the same temp is not moving from half way mark ,so fingures crossed it solved the problem .

I'm having these same issues again, happened 2 years ago. The head n block was shaved, new gasket. However it seems they're warped again. Temp gauge never pass half. There's coolant in the oil. Rough idle and power loss. Shaving this head n block again making no sense to me...

What's the avg price of a head n block?

I also read on other forums the cat converter disintegrates (was part of a recall) and messes up the cylinders. Also read the bit about the head bolts stretching.

What do I do?

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Best bet is look into gettinga fu head and block if possible , along with some arp bolts or some type of new bolts, the firm might have. This needs to change along with a head and block.

an idea is to pm anil sooknanan on the forum, as he knows where you should start to look for the head and block or a possible engine conversion to a sr20vet if you like, seeing these vehicles came with them on certain model

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for the guys who've been having the head/block warping issues with the QR20, may I ask what oil you're using? You'd think its unrelated, but please state, these engines are NOT supposed to overheat/warp to the extent that this is occurring. Please post your oil brand and body, also the coolant you use. Thanks

ended up getting a head n block in le bamboo for $6k

brb swappin

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Castrol Edge 5W50 syntec

Prestone coolant...was using "genuine nissan coolant" first time it happened...

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As someone mentioned earlier, and as I read on other forums...I believe the culprit is crappy head bolts...because in both cases my head gasket was fine...no signs of "blowing" per se...but the head n block warped a bit...temp gauge never moved either...

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I've noticed a very high rate of failure on the nissan lean burn engines. Thing is lean burning engines would run hotter, but I would think they'd be engineered to handle the high temperatures. This is very interesting. makes sense that it could be head studs, many factory head studs are the stretch type. I wonder if the extra heat coupled with the stretched head studs could be the cause of failure...Any of you guys ever tried upgrading to some ARP studs?

Also I'm reading the cat converter also disintegrates (on older models) and can wreck your cylinder walls...

http://www.nissanforums.com/x-trail/798 ... lem-2.html

They suggested getting rid of the stock manifold/headers and go with an aftermarket cat. converter setup...question is...where do we get it locally?

A local mech also told me get rid of the cat converter totally...

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the local mechanics are on to the fact that cat converters contain precious metals, the scrap iron buyers pay a premium for cat converters now, hence why mechanics are widely recommending the removal(might be different in this case though).

So I read the thread, you might really be better off removing the cat. Would be very important to use a good coolant as well, silicate free, to maintain maximum cooling...Zeerex for asian vehicles is really good.(check MG man). Looks like materials problems from reading the thread though.

My experience with these engines leads me to believe that one of the causes of this problem is the reuse of the stretch head bolts.
When I trained at Renault in France they advocated replacing stretch bolts every time they were removed. We all know that that is not going to happen here in T&T. but the factory service manual shows how to measure the head bolts to determine if they need replacing.
The problem with the bolts is that after many heat cycles and reuse, they do not have the same tensile strength and clamping force as when they were new, add that the fact that not every mechanic uses the specific tightening routine for these heads (which I posted earlier) and the result is recurring head gasket failures.

So if say one had a fairly newish engine...wait for the headgasket to blow then change the headbolts?

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The rule of thumb is that when you TTY head are supposed to be changed when removed because of the stretched threads. I am not sure if this engine carries the three pc metal shim type head gasket, if it does than the this type of gasket does not help seal off any imperfections on the head of any change in clearance due to a slight raise of temp. as the older paper type/composite type gaskets used to .

Yeah it's metal shim, so what do we do?

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the fel pro head gaskest(blue) have a coating that when heated up flows and seals minor imperfections in the head. I dont know if its available for your application though.