2nd Engine Failure, I am mystified!

[nicofost Lurker Find all posts View Profile Close nicofost]

Hello Everyone. My car (120 series D4D engine) and camper trailer have just arrrived back from Kununurra on a truck where we unfortunatley suffered a second engine failure half way through a year long around Australia trip. I am currently a little mystified as to the cause of the second failure and hoping that someone might be able to provide their thoughts on how to progress. The facts so far:

1. Engine was rebuilt (long engine) 80000kms ago after two pistons cracked. I bought the car second hand approximately 30000kms prior to this engine failure. Injectors were only 30000kms old and well within spec at time of failure. Engine is stock standard, no chips, aftermarket exhaust etc.
2. Fast forward to a few weeks ago. We had just left the Gibb River Rd (thankfully) and were travellng on the bitumen at 100km/hr. The oil light came on and I pulled over straight away and turned the car off (within 30 secs) but the damage had seemingly been done. There was no other warning noises or lights (if you ask my wife she thinks I am quite paranoid re noises etc as I like to pick up potential problems early). I restarted the engine to find it running very rough and making some very unpleasant noises. There was also some smoke (burning oil) coming out of the dipstick and oil fill opening but the oil level was good. We had the car towed as I knew it was bad and didn’t want to further damage the engine.
3. We had covered 20000kms on our trip so far and I had changed the oil every 5000-6000kms.
4. Mechanic confimred engine rebuild required by listening to it.

So today I checked the pickup screen in the sump and it is as clean as a whistle. Then I had a careful look in the sump and if you look at the second photo you may be able see something that shouldnt be there. Yep, that is a bolt. It doesn’t look like it has been clanging around the engine and I certainly didn’t hear anything. There was also some small metal shavings in the sump. Not good.

So, my thinking is that it must be an oil pressure issue, something wrong with the oil pump?

I would really appreciate your thoughts on this before I start doing compression tests or trying to access the oil pump.

Thanks.

Nick

[red hilux Member Find all posts View Profile Close red hilux]

so sorry to hear mate.

Im guesing its a something thats come loose during rebuild time

[carco Advanced Member Find all posts View Profile Close carco]

This is the only shoulder headed bolt I can think of. (Balance shafts)

[t303 Senior Member Find all posts View Profile Close t303]

Bolt backed out of the oil pickup mount, broke the suction? I can see one bolt in the picture, other is masked.

[krypto Avid PP Poster! Find all posts View Profile Close krypto]

From an engineering perspective so soon after a rebuild I would strongly suspect a fault in the re-built engine. An incorrectly tensioned bolt or poorly machined part will not necessarily fail immediately but may cause a delayed failure like you have experienced. The fact that you have had two failures is probably not related, unless you do something really bad and 8000kms is not far even if you do.

[nicofost Lurker Find all posts View Profile Close nicofost]

Thanks carco, I wonder if one of those bolts could make its way to the sump. Read on though as I have done further investigations today and it may well be related.

Both nuts accounted for t303 that attach suction screen.

Basically krypto, you are on the money. Upon further investigation this morning I noticed another bolt caught in a void in the main sump. I fished it out and low and behold it is one of the special banjo bolts that hold the piston oil squirters on. This explains the low pressure oil light as once this bolt which has a check valve in it comes off pressure would drop in the system. I am hoping that no further damage was done to top end in the short time it took for me to turn the engine off and in the few minutes running I suspect the truck company drove it getting it on and off trucks.

My thought is that the engine rebuilder (who will remain nameless until I speak to them tomorrow) just finger tightened the banjo bolt and it gradually worked loose no doubt helped by the corrugations of the Pilbara and Kimberley.

The question then was where was the rest of the oil squirter assembly? I ended up taking the sump off and found the nozzle part jammed up between one of the balance shafts and the case. I managed to get the part out, (see photo) and unfortunately the balance shaft gear is worse for wear. There may also be collateral damage on the injection pump gear.

So, my next step is to ring the engine builder and aim for a repair at their cost. Failing this, I will continue to pull the engine apart and replace the bits necessary and hope that the low pressure situation hasn’t damaged anything else.

[carco Advanced Member Find all posts View Profile Close carco]

So it was the shoulder bolt in the sump photo, not the banjo bolt?
Therefore you're still looking where the shoulder bolt came from and the only place I can think of is both balance shaft gears.
With the centre bolt gone the balance shaft gear can walk on the shaft, perhaps chewing into the timing cover.
Oil pump will have ingested bits of metal so it may not look too pretty.
You'd have no confidence in the engine build now, what else had been left half tightened?
Search is really poor on this site but I seem to remember another D4D post where the balance shaft bolts undid themselves on a factory built unopened engine.

[carco Advanced Member Find all posts View Profile Close carco]

Found it.
https://www.pradopoint.com.au/forum/...what-a-feeling

[nicofost Lurker Find all posts View Profile Close nicofost]

Yeah, that is correct carco only the shoulder bolt was in the sump. The banjo bolt was just above the bottom sump in a little nook.

Spoke to engine rebuilder and got the fob off. Will take it to fair trading.

[nicofost Lurker Find all posts View Profile Close nicofost]

Thanks for the link as well carco, makes for interesting reading. It definitely sounds like it is possibly one of the balance shaft bolts. Wonder if anyone wants a Prado cheap. It is a shame because the rest of the engine might Ben totally fine.

[Guest Close Guest]

Thanks for the link as well carco, makes for interesting reading. It definitely sounds like it is possibly one of the balance shaft bolts. Wonder if anyone wants a Prado cheap. It is a shame because the rest of the engine might Ben totally fine.

I would highly suggest you would have a case against the engine builder. I would not be stripping anything further down and seek some advice from your local consumer protection agency.

[GX-D4D Banned Find all posts View Profile Close GX-D4D]

Yep x2 what piggy said and make sure you have plenty of photos to back up what you already done. They'll try anything to wiggle out.

[nicofost Lurker Find all posts View Profile Close nicofost]

Thanks again everyone. The engine rebuilder was very difficult and suggested there must be another problem. He did not even offer to look at the car. I have lodged a complaint with NSW fair trading and see what happens.

[Pradosaur Member Find all posts View Profile Close Pradosaur]

Good luck

[Guest Close Guest]

Thanks again everyone. The engine rebuilder was very difficult and suggested there must be another problem. He did not even offer to look at the car. I have lodged a complaint with NSW fair trading and see what happens.

Speak to your local motoring association. RAA in SA Racv in VIC, etc. they would be the ones to likely strip the engine down and ascertain the issue. Have them or some other mechanical engineer do this before lodging court proceedings or further fair trading action.
as you will need the ammo. You can also then approach the engine builder if it is deemed they were at fault. Offer them a way to sort it before litigation.