GU 4.2 Head Gasket

Hi al,

Have done a bit of searching but haven't found any topics that suit (happy to be corrected). My 4.2L was rebuilt about 18 months ago now and it appears to have done a head gasket.

Started out that it was 'using water' but has now progressed to the bubbling of a cylinder when radiator cap is open. There does not appear to be water in the oil though. Haven't cooked it... Have just nursed it home.

Now, a couple of questions;

1) how much would (should) I expect to pay to have it fixed?

2) given its not done a huge amount of driving, what could have caused this? (I replaced viscous hub etc when I rebuilt)

3) is it worth getting the head tested or just replace given its seen a bit of heat in its lifetime?

4) with the right tools, how hard a job would it be to do at home?

I had a 12 month warranty (guarantee?) on the rebuild which has since passed obviously... Have hardly driven the car though so frustrated that it's happened now. Guessing I'd have very little luck unless the guy was in a god mood.

Apologies for the long post. Just trying to get as much info as I can to work out where to go from here. I spent a LOT of money I didn't really have on the rebuild so I want to have as much info before I begin this time.

Cheers

Ben


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1) To have it fixed by a shop if the head is ok then expect $1000-$1500.

2) How many km has it done on this rebuild? Unfortunately the fact this has started after a rebuild isnt a good sign. It is common for liners to drop if incorrect practices have been used. If the liners have dropped then you will more than likely need a new block. I do hope this is not the case. Also if liners werent replaced with the rebuild then dont worry.

Did you use the correct torque procedure on the headbolts?

3) testing doesnt usually cost much and if its fine then being able to reuse will save you a bit of coin. It is also best practice to face the head as well.

4) Not hard to do at home. The most time consuming pary is cleaning everything.

Thanks mate. Kms wise it's probably done maybe 10-15k or so. Maybe a bit more but not enough for a head to go I wouldn't think.

Rebuild was because I melted Pistons. I really can't tell you what he did or didn't do as that was a complete debacle. Also got the block back with the head on it so I presume an engine joint would use correct procedures (but again who knows). He did come recommended from a few people but was a job on the side so who knows if shortcuts were taken.

Guess I'll have to cross my fingers that it's not the liners. No way I could afford a new block.

Was quoted (sight unseen) by a neighbour about $4000 - $4500 so guessing that's the "I hate working on 4wds" price...


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Hey Ben give Biders a call in Cranbourne and ask him his thoughts and a price scale. He won't bullsh1t you and knows Nissans. He races at the pointy end and is very good at what he does.

Good luck with it mate.

Thanks Darren. Will do my best to give them a buzz. Hardest thing has been finding time of late.
Always good to get a recommendation :)


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So I've called Biders and have booked in for a diagnosis on Monday. Wasn't behaving the same on the weekend when I fired it up to show the old boy so now back to not being 100% sure. Time for some experts to have a look.
Keep you posted...


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Quote:

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Originally Posted by relyimah

Thanks mate. Kms wise it's probably done maybe 10-15k or so. Maybe a bit more but not enough for a head to go I wouldn't think.

Rebuild was because I melted Pistons. I really can't tell you what he did or didn't do as that was a complete debacle. Also got the block back with the head on it so I presume an engine joint would use correct procedures (but again who knows). He did come recommended from a few people but was a job on the side so who knows if shortcuts were taken.

Guess I'll have to cross my fingers that it's not the liners. No way I could afford a new block.

Was quoted (sight unseen) by a neighbour about $4000 - $4500 so guessing that's the "I hate working on 4wds" price...


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Look like it's a bottom end rebuild. It doesn't look like the top end was done other than a new head gasket.
That might explain the drama.
How did you melt the pistons?

You are correct Dom. Was told the head was ok.

Pistons were melted due to a hole in the radiator on a 40 degree day that I did not notice until it was well and truly too late :(


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I bet my left lug nut its got a cracked head. I also wouldn't be going back to that same mechanic ever again. When my radiator blew I was stuck in middle of nowhere & out of necessity in an emergency situation I overheated mine to the point smoke was billowing out of the engine bay. 2 yrs later it was still driving fine until I hydraulic locked it in a river & bent 2 rods. I made them test my head while it was off. Turns out it had 9 cracks in it, yet it still ran fine.

Quote:

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Originally Posted by relyimah

You are correct Dom. Was told the head was ok.

Pistons were melted due to a hole in the radiator on a 40 degree day that I did not notice until it was well and truly too late :(

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Yeah but they can't say the head was ok by just looking at it though. It's always good practice to get it tested while it's out as it only cost peanuts, comparing to a full rebuild job.
Make sure the water is not loosing via any possible inlet manifold water lines and evaporate into the intake or slowly seep out of the intake manifold.
. I'm not sure how it's setup in Diesels, so have look in the Haynes or Factory manual.
Once you made sure it's the cylinder head, then you can pull it out and have it tested and reconditioned.
Perhaps better to get a swap over reco head from a place like Allhead etc. http://www.allhead.com.au/

Thanks Dom. I can only make an assumption that they had it crack tested as I was not there. As they are an engine centre I guessed they would do the right things.

Taking it to someone Monday to get them to diagnose. May end up expensive but I don't have the room at home at the moment so very little choice. Hoping for something "simple" like you've suggested above though.


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So, an update (hopefully a final one) -

Took it to Bidders under Darren's suggestion. He is a great bloke to deal with. Turns out head was cracked over 4 cylinders, and radiator was stuffed.
So new head, new radiator and new bottom hose (after a small mishap) and I managed to get from Frankston to Heathcote yesterday in 42degree heat and the temp gauge didn't move at all!

Very happy camper at the moment.

Cheers for everyone who pitched in with advice

Ben


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