GU Patrol 2.8 erratic engine noises
Submitted: Friday, Jun 17, 2005 at 19:39
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Selastic Man
Hi all,
I have a problem with my 2.8td which nobody seems to be able to fix, maybe someone out there might've had the same problem.
The motor makes a erratic tapping noise as if the timing keeps altering while driving, It's really starting to irritate the hell out of me. One minute it will be quiet and smooth, the next it will be noisy, no matter what revs im doing. I have only done about 10,000 k's since I had the motor rebuilt so I took it to the so-called mechanic that built it and he says it could be a timing sensor, but he is not sure as he hooked it up to diagnostics which reported no problems. He then said drive it until the dash warning light comes on.
Can anyone help with some expert ideas!
Reply By: desert - Saturday, Jun 18, 2005 at 15:58
Saturday, Jun 18, 2005 at 15:58
You mean how long is a peice of rope! Look, it sounds like a mechanical fault to me, but defining it is the hard part. Short of pulling apart the engine again and going over every part with a fine tooth. I would suggest the following course of action in an attempt to make the fault reveal itself: Change the engine oil and filters again, start again with fresh oil and filters.While you have the oil out, closely examine for metal fragments. If OK, drive the car as per normal for 5000kms, then drain the oil and inspect once more. If the noise is no worse, then repaeat this process once more. If noise is worse we move to the next step.viz, contact an analytical laboratory (try ringing Caterpillar and see if they will give you a contact), then send an oil sample away for analysis. The report will determine if any metal to metal wearing of parts within the engine is dropping metal particles into the oil. From these particle they are able to tell the type of metal and therefore the most probable part that is in question. Different internal parts are made from different metals, you see. Once this has been diagnosed, you are in a better position to be able to say what is wearing, or about to fail. Remedial action can then be taken, once you know where exactly to look, given the lab results.
AnswerID:
116252
Follow Up By: Selastic Man - Saturday, Jun 18, 2005 at 18:18
Saturday, Jun 18, 2005 at 18:18
Thanks Desert for
the tip!
I will do that since my next oil change is coming up shortly.
But i dont think it is mechanical, it seems to behave more like a sensor problem as it is not constant, it is hard to find good info about these 2.8td motors and with it being totally controlled with senors, its hard to self diagnos. Its even difficult to alter the timing because the computer sences that something has changed and resets itself (correct me if im wrong). Is there any good sites I can visit that will give me more info about these motors?
FollowupID:
371820
Reply By: rolande- Sunday, Jun 19, 2005 at 10:50
Sunday, Jun 19, 2005 at 10:50
G'Day,
Mine was very quiet until I did the 200,000k service, and changed the injectors. Old injectors fine, new ones have an annoying "tap", but not always.
No help from mechanics, etc, but suspect the injectors to be the cause as other than seals, timing belt, etc, nothing else was changed.
Three oil changes later as it hasn't stopped
Rolande
AnswerID:
116332
Reply By: Member - Matt- Monday, Jun 20, 2005 at 14:42
Monday, Jun 20, 2005 at 14:42
G'day Selastic man, please bear with me as you read... a work mate had a similar thing happen with his 2.8 and swore black and blue the motor was gone. The noise was intermittent and would never perform when at Nissan or at the
shop that ultimatley fixxed it. (Robson Bros. in
Perth) The noise was metalic and rising and falling with the revving motor. The owner of the patrol who has experience with trucks, motor bikes and cars was saying it was internal noise requiring a strip down and rebuild. Robsons eventually located it to the fan, power steer belts etc !!
After replacing all belts, the noise has never come back, and this was atleast 3 months ago. The owner still says that after hearing the noise he would have never ever expected such a metalic noise from a rubber belt.He still laughs in disbelief. One last thing, the design of the tensioning system for the GU belts let you easily over tighten the belts if you're too keen on the ratchet.
Hopefully this is your problem, as belt are cheap... matt
AnswerID:
116545
Follow Up By: Selastic Man - Tuesday, Jun 21, 2005 at 19:37
Tuesday, Jun 21, 2005 at 19:37
You could be right on the money!
After reading your post i went and checked the belts and found them to be fairly tight (too tight infact!) and also noticed that the a/c pump was on a slight angle, just enough to not look right. It woke me up a bit because like i said earlier, I've only done less than 10,000 k's since the motor was rebuilt and had taken the truck back to the mechanic twice, and he never noticed it either.
So I will be replacing the belts on the weekend and see if that does the trick.
Also, has anyone removed the clutch fan on a diesel and replaced it with a set of thermos? I used to do this in the old days on my little 73 lancer rally car to reduce drag on the motor, it made a slight but noticable difference!
FollowupID:
372251
Reply By: Member - Matt- Tuesday, Jun 21, 2005 at 23:18
Tuesday, Jun 21, 2005 at 23:18
Hi Selastic, don't go changing the belts if they're not starting to crack, 'cos from experience on the side of the road at night, it is a dog of a job. Try backing of the tension if too tight, as an idea, you should be able to twist the belt 90 degrees, eg: the flat block section of the belt that sit horizontal in the valley of the pulley, can twist around to vertical with moderate force from your thumb and finger. Once this is done you can then put rubber grease on the belts, or my preferance of normal clear selastic... fair dinkum Silastic man, the silicone is a lubricant, so use about the same amount as tooth paste on a brush on each belt, shared between the three surfaces of the belt that contact the pulley.Then start her up, this should quieten the motor sooo much that you'll be able to hear diesel dripping back into the tank from the return line. Let us know the out come,
Cheers matt
AnswerID:
116820