Isuzu Trooper Owners Club UK™

[Lobster]

Hi All
My 04 Trooper 3.0 has been in the garage since February!
Local garage took it in to replace glow plugs (3 had failed): glow plugs had seized: head removed and heated up to remove plugs: head skimmed and new 'o' rings fitted in injector sleeves: head refitted with appropriate gasket: car won't start! The garage owner didn't know why so he took the head off again and sent it back to the company that had removed the plugs and skimmed the head to be checked again.
Everything ok, valve timing and seats checked again as well, all ok. Local garage replaced the head and car still won't start!
After three months of scratching his head, he took the car to Hylton Isuzu - Shrewsbury and they have had it since. Diagnostics all ok, but low compression is showing across all four cylinders.
The car was running and starting well (even with 3 dodgy glowplugs) before it went into the local garage, it has only done 38,000 miles from new and has a full service history, so I don't think the low compression is down to engine damage/wear, it has to be something to do with the cylnder head.
Has anyone got any ideas or advice please?

[Wirdy]

Official Isuzu advice.  3.0 heads should NOT be skimmed.    

Bad advice / work by your original garage.

That could be the root of your compression troubles if the head gasket can't make a good seal anymore due to the skimming.

Doesn't explain the original non-start, but that could have been something simple like fuel / oil priming (can take 2 full battery charges of cranking to get the pressures up), or a simple ORPS problem.
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2001 3.0 DT LWB Duty - Dragon Green Metallic.

[Gribble]

Hi, I would guess that they have timed it wrong which is why it wont start ,this could be confirmed by asking the man who put the head on which marks he used.
I hope he paid for the second set of head bolts as they are the stretch once and throw away type ?

They would have had to strip the cams out to skim the head so you would hope they kept the valve  buckets and shims to the original locations and dont think its hydraulic tappets - dont laugh its happened on here before -

As for the low compression do you have a figure or are they saying its just 'low' ?
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[Lobster]

Some good points to look at there, particularly the head bolts - I'm quite sure he used the same bolts on both times he fitted the head.
The local garage have had two goes at checking the timing now and have assured me this is spot on, Hylton Shrewsbury have also confirmed the timing is correct.
There was no original starting problem Wirdy, I just noticed that over last Winter the car took a few seconds longer to start on frosty mornings. I suspected the glowplugs and three of them had failed, other than that it started and ran perfectly. It's a mystery right enough, but it's getting beyond a joke now having been with (my main car) since February! Many thanks for your help fellas.

[Gribble]

Well all that leaves is the lack of fuel to the injectors or oil presure for the injectors is not being  raised.

The tech 2 will show if the oil pressures not up and say injectors disabled so that should be easy to spot and the fuel pressure is just pump the primer till some pressure is felt.

No oil pressure and no fuel up wont show on tech 2 as a fault as they are variable inputs with no DTC number being set .

On the timing it may well be lined up on the top and bottom  timing belt belt drive pulleys since this seems the ovbious marks to use  but it has to be done off the crank pulley and that mark is hard to find without prior knowledge or removing the lower soundproofing so the TDC timong cover  mark can be seen ,its an easy mistake to do but I have seen it done on 3.0's .

This is because the mark on the lower timing belt pulley is part of a series of dots and V's that only line up ever 70 or so turns of the engine as they drive the balancer shafts as well and are normally used when you do a rebuild .
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[eithan h]

don't worry about the oil pump pulley as gribble says as long as the crank and cams are on tdc then thats good enough, also when the cams are on tdc check the slot in the back of both cams are parallel to each other and run  level with the edge of the cam carrier so you could in effect place a bar in them and sit it on the carrier if you know what i mean!
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roll on christmas!

[Lobster]

Just spoken to Hyltons Isuzu - Shrewsbury and they can't start stripping/investigating until the end of August; that will mean the local garage had it (my main car remember) for 4 months and Hyltons for 3 months and still no working vehicle!
What would anyone guess my liability to be with this job, bearing in mind that the car only went in for glowplugs? If my local garage have messed things up with the cylinder head (the car was running perfectly when it went in to them) should they be covering Hylton's costs do you think? Should they have even skimmed the head or should they have fitted a new one as Wirdy suggests above? The garage isn't big enough to have courtesy cars etc so I have been borrowing various 4 x 4 and running about in my Son's P reg Corsa.

[Wirdy]

Official Trooper manual page 6A-6 in black & white ...Cylinder Head...."Cannot be reground".

The relatiionship between piston projection above the block face at TDC is critical and also detrmines the thickness of the head gasket (they come in three different thicknesses 1.35mm, 1.40mm, 1.45mm or one/two/three notch as shown by the notches on the edge of the head gasket), hence the head clearance has to remain constant, i.e not skimmed.

Isuzu advice is to replace the head if warped.
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2001 3.0 DT LWB Duty - Dragon Green Metallic.

[Gribble]

I would show the manual to the head skimming garage and say , well you did that and now it wont start, please tell me what you are going to do to put it right ?

Now its possible that the thickest gasket might fall into the Isuzu  spec for piston protrusion depending on how much was skimmed off but you wont know till its stripped and measured.

My money is on wrong timing for the non starting because if the tech did the head bolts up to the right torque then angle he would have seen they were stretch bolts so whats he used to time it ?
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[Wirdy]

General question Gribble, apart from ordering it correctly and getting it in the correct packaging, how do you know a stretch bolt is a stretch bolt?    and do they stretch enough that they can be measured as 'stretched' by a joe bloggs with normal measuring equipment like myself?
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2001 3.0 DT LWB Duty - Dragon Green Metallic.

[eithan h]

generally if has a degree torque to it it's a stretch bolt as this puts the bolt in to it's elasticity stage and yes there is a length that if they exceed you throw them away, you can normally measure them with a tape measure if you need to check.
but i have had trouble when reusing them again so now i just use a new set everytime as it's not worth the hassle when it comes back.
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roll on christmas!

[Gribble]

As eithan says there is a maximum length they can be  before you need new but some makers say new each time .
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[Lobster]

Hi Wirdy, do you have a link to where I can find the official Trooper manual and the relevant section i.e page 6A-6?
Should I cut my losses, ignore all the work that's been done and just buy a new head do you think? Many thanks for the help.

[TimBanham]

Difficult to call on cutting your losses - I would try pointing out to the garage that did the skim and say what are you going to do about it?

if you do go down the route of new head there are a number of 3.0 being broken on that well known on line auction site.

Also I would ask the isuzu dealer you took it to why they didn't point out the fact that the head shouldn't be skimmed?

Also have you paid out any money yet?
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3.0TD LWB Citation

[Lobster]

Thanks Tim, I will ask Isuzu why they haven't pointed this out. I haven't paid any money out for this job to date; it would seem fair for me to have to pay for a new head if that is the official advice, but not for everything that has gone before if that was contrary to official advice.