GQ 4.2 Oil burning

Submitted: Saturday, Jul 05, 2003 at 20:18
ThreadID: 5831 Views:5676 Replies:5 FollowUps:6
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Hey all,

for the mechanically minded out there, my gq uses/burns about a litre of oil every 1000 clicks. Apparently the satndard compression for the gq is around 2950kpa (428psi). To work out whether it was rings or valve guide/seals responsible for the oil consumption i did a compression test.

The compressions for all cylinders were between 3050 and 3300kpa on the starter motor,higher than the recommended in the book, is this okay? I also assume if high numbers is good then the oil burning problem i have is associated with the top end of the motor. Valve guide seals seem the only option.

I believe these can be replaced without removing the head, some special valve compressor from the top, can anyone fill me in on this process etc and all other comments would be appreciated.
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Reply By: Chris (W.A.) - Saturday, Jul 05, 2003 at 21:09

Saturday, Jul 05, 2003 at 21:09
obviously the engine we're talking about is a diesel, td42, is the vehicle used for short trips around town? Depending on how many kms for the amount of oil consumed I would say possibly cylinder bores glazed. if high kms I would say valve guides (valve stem seals). Yes, valve stem seals can be changed without removing cylinder head. It's a matter of supplying compressed air to each cylinder at a time at tdc with rocker gear removed, you'll be able to remove valve springs and replace stem seals as required. If engine has low kms have been told by many old diesel mechanics that bonami or ajax powder down air intake at 2000rpm is a non rebuild alternative to de-glazing cylinder bores.
If you think valve guides are at fault remove exhaust manifold and look for evidence of oil behind exhaust valves.
Regards,Gibb River in July.
Chris
AnswerID: 24286

Follow Up By: GOB member vic - Saturday, Jul 05, 2003 at 21:46

Saturday, Jul 05, 2003 at 21:46
before you try the bon ami cure go back thru the forum there was something about it and the damage it does
steveits arrived just got to get photo and download
only 35 sleeps to go then off nth to darwin yeah
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FollowupID: 16351

Follow Up By: crowe - Saturday, Jul 05, 2003 at 22:11

Saturday, Jul 05, 2003 at 22:11
sorry guys, a bit vague on some details. The motor is diesel and has done 270 clicks, not generally used for short trips around town, from what i can gather it has had a hard life pulling lots of weight. It does blow smoke at startup and after idling a while but difficult to attain how much burning it does when driving on hwy.

From my understanding this points moreso to valve stem seals? Dont think i'll be going down the ajax route just yet
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FollowupID: 16352

Follow Up By: Chris (W.A.) - Saturday, Jul 05, 2003 at 22:44

Saturday, Jul 05, 2003 at 22:44
I'd never use bon ami either - you'd be crazy to, just said it because old mechanics remedy to smoky detroit diesels.
It's all w*nk. Nothing in a bottle or anything as a quick fix can replace worn metal.
Rip it out and rebuild it.
That's the only true cure regardless of kilometres (who know's the history of the kms travelled depending on the driver).
Cheers
Gibb River in July.
Chris
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FollowupID: 16355

Reply By: Eric - Saturday, Jul 05, 2003 at 21:54

Saturday, Jul 05, 2003 at 21:54
crowe.
I have done the oil seal change without taking the head of, but it is not worth doing if the motor is that tired the head will nead cleaning and the valves reground, The oil consumption can be due to worn or stuck oil rings that do not show up in a compresion test. The time taken to get the head of is about the same as fidling with the air pressure and trying to get the collets out, whatever you do, do not put an abrasive in your motor that is only done when a motor has been rebored and was not honed, Eric.
AnswerID: 24289

Reply By: Truckster (Vic) - Saturday, Jul 05, 2003 at 23:35

Saturday, Jul 05, 2003 at 23:35
Give it a christmas, a head job is around $750-1000 tops. While its off measure the bore, and check for slop in pistons... will give you a better idea.

200,000 is nothing for a well loooked after TD42, Nick W on GQ list has 530,000 on his 89 model.
AnswerID: 24297

Follow Up By: Martyn (WA) - Sunday, Jul 06, 2003 at 20:20

Sunday, Jul 06, 2003 at 20:20
You forgot to mention, make sure you have access to a recon head just in case, the heads have a habit of cracking between the pre-comp chamber and the exhaust valve. Check number 4 cylinder first.Keep the shiny side up
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FollowupID: 16376

Reply By: Member - ADRIAN- Monday, Jul 07, 2003 at 13:31

Monday, Jul 07, 2003 at 13:31
CHECK POST 5355 REPLY 8
THIS DOES APPLY TO PATROL DONE HEAP S OF THESE DID ONE LAST WEEK
THESE ENGINES WILL DO MORE THAN 500K IF LOOKED AFTER.
THE ABOVE MAY BE PROBLEM COILD SAVE YOU HEAPS .OK PUMPS MAY COST ABIT
BIT NOTHING LIKE A REBUILD, AND YOU WOULD STILL HAVE TO REPAIR PUMPS ANYWAY HOPE THIS HELPS PS DONT USE BONAMY THAT WILL WRECK YOUR ENG. FOR SURE GOOD POWERFULL DETERGENT WORKS WELL WITHOUT WEARING OUT THE RINGS ETC.
INTERESTED TIO

KNOW HOW YOU GET ON dmech
AnswerID: 24397

Follow Up By: crowe - Monday, Jul 21, 2003 at 16:25

Monday, Jul 21, 2003 at 16:25
Adrian,

thanks for the advice, i read the post and have removed the return banjo bolt, there was a noticable blackness in the diesel and some slight staining of the bolt. Is there any more detail you can give me, what sort of price is it to get this fixed? can i just change the front oil seal and hope for the best rather than spending big dollars on the pump as everthing else is okay?

I have cleaned the bolt and recess, i will run it for a few days and see if the staining comes back.

cheers, crowe
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FollowupID: 17269

Follow Up By: Member - ADRIAN- Friday, Jul 25, 2003 at 01:01

Friday, Jul 25, 2003 at 01:01
CROW
you will have to remove pumps from eng. to replace seal make sure that all t/marks line up etc [ on gears] seal only replacement is easy jus pry out old one press in new one might buy you some time,however shaft usualy wears as well on these units. seal cost about $9
parts to replace shaft /top cover seal/ gaskets /supply pump etc normaly about $200.00 labours a bit dear as you do need to know what your doing inside regards adrian
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FollowupID: 17556

Reply By: colin - Thursday, Jul 10, 2003 at 14:42

Thursday, Jul 10, 2003 at 14:42
try changing the brand of oil you use i run valvoline turbo oil and use not a drop tried castrol and found i started to use oil so went back to valvoline no more usage vehicle has done 260,000ks may take a couple of services to see a difference. Col
AnswerID: 24598

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