Gu td42ti Ute cold start engine rattle

[Badger]

Hi all its been quite awhile since I posted a thread on the forum but I have a problem I can't solve and I am hoping someone can offer some advice that will help me fix the issue I am having. I bought an 04 gu cab chassis with td42ti engine that has almost 300,000 kms on the odometer. I purchased it just before Xmas last year. When I first bought it and for several months after I had no concerns at all everything mechanically seemed as it should be, but as the temperature started to drop as we moved into the colder months an awful engine rattle developed when starting from cold first thing in the morning and what I find even stranger is that the noise is worse the lower the temperature is. The noise is horrendous, it sounds like it's about to throw a rod out of the side of the block or something that sounds just as awful (and costly) as that! The noise does disappear after the engine warms up and once it is warm the engine sounds like it should, the same as the other td42t engines in my other utes. It sounds like severe diesel knock almost. I took it to a guy I know who has a well known and respected auto workshop and he personally has had and still has alot to do with patrols. The engine was warm when I got there and he said it sounded beautiful idling over as it was, then I played him a couple of videos of the cold starts on different occasions and he said that it certainly didn't sound good but had no real opinion on what it could be. He did say he had heard another td42ti some years earlier with a very similar horrid noise but he was unsure what the guy who owned it did ( if anything ) to rectify the issue. He could remember the guys name and I tracked him down and asked if he managed to fix the problem, he said he had and in his words he told me that he had replaced the crank angle sensor and ever since it was quiet as a mouse. I thought awesome that's an easy fix so I thanked him and was on my way. After further research I discovered the td42 engines don't have a crank angle sensor they have a tachometer revolution sensor. So thinking that's what he must have meant I ordered a new one of these sensors. On the day I picked it up I had already driven the Ute so after I changed the part over the engine block had cooled down to about 15 degrees Celsius ( I have a temperature sensor on the block with a digital readout in the cab ) and I could have sworn that when I started it up after putting the new sensor on that it was in fact much quieter and I felt that way for the next couple of days on the first cold starts of those days as well. After a few days though the noise seemed to be just as horrendous and worrying as it had been before buying the new sensor. Maybe it was a kind of placebo effect I experienced with my mind telling me the guy said this fixed his problem so surely it will mine as well. Who knows, but it's still there and I would like to hear from anyone who has experienced something similar to this noise or can offer advice and or suggestions to resolve the problem. I would put up the videos of the cold starts so u could hear them yourselves but I am not sure how to go about doing that. Thanks in advance for any replies.

[mudski]

Are all the glow plugs working? Sounds like a fuel thing. Like the fuel not igniting properly due to cold cylinders.

[Stropp]

Is it stock as mine has the same issue when cold but I have an 18g turbo and 12 mm boost compensated pump, apparently it’s because the timing is advanced

[Badger]

Hi thanks for the replies, in reply to mudski I haven't tested the glow plugs I am hopeless when it comes to electrics but I will take it over to a mate of mine now who is pretty good with electrics and we will test them now. I will let u know whether they are all working later tonight. Stropp, yes it is standard it still has the standard turbo, only thing that's been modified is it now has a 3 inch dump pipe and exhaust system. I am trying to work out how to upload these videos so u can listen to it. I will go test these glow plugs now and get back to u. As far as I am aware the pump timing hasn't been touched, if they have been advanced don't they become hard to start when they are warm? Or is that not so because I have no issues with starting hot or cold Thanks again

[Badger]

Mudski u may be onto something. My mate wasn't home so I broke out the multumeter and from what I can gather the glowplug resistance when they are out of the vehicle should be 1 ohm or very close to 1 ohm. The first glowplug I tested was bang on that mark after i deducted the 0.4 ohms resistance that comes from the multimeter itself ( please someone correct me if i have it wrong ). The second one I tested doesn't even register on the readout. I have it set on the lowest setting of 200 ohms and it's not giving a readout so I am thinking the resistance of that glowplug is in excess of 200, so it has to be buggered. That's as far as I have got so far I will continue testing the rest but I will buy a new set in the morning and with any luck that will solve the problem. I will let u know. Thanks mudski for the suggestion even if it doesn't fix the issue I still needed new glow plugs anyway ( if I am testing them correctly that is ).

[mudski]

I've never had the need to test glow plugs so I can't help. Im sure someone here or Youtube can assist with that. But I do know, my TD rattles and carries on like a two bob watch on super cold mornings until theres some heat in the cylinders. I usually just glow the plugs twice before start up.

[nissannewby]

1 ohm is the number. Anything more and there is a problem. Also the td42ti has some other things happening with the small amount of electronics it has on cold start up. I doubt the rpm sensor has anything to with the noise but there is a coolant temp, injection pulse and timing control solenoid that do. But it seems like you have found the problem.

The glow plug timer should also function it a way that it powers the glow plugs in a cycle until a certain temp is reached.

[BrazilianY60]

It seems that the actual glow plugs test is just for continuity. The (dedicated to the glow system) water temp sensor is the one that needs to be tested for resistance according to temperature. Here are the pages from the FSM.

85752

[Hodge]

Without hijacking the thread (apologies)...
But is there a period plugs should be replaced within in ??? My 06 TD just hit 170k. And even on coldest mornings it starts and runs fine , every time.
Or only if they start playing up ?
The glow plug relay goes off when the coolant temps hit 30-32c on my car.

Sent from my Pixel 6 using Tapatalk

[mudski]

Without hijacking the thread (apologies)...
But is there a period plugs should be replaced within in ??? My 06 TD just hit 170k. And even on coldest mornings it starts and runs fine , every time.
Or only if they start playing up ?
The glow plug relay goes off when the coolant temps hit 30-32c on my car.

Sent from my Pixel 6 using Tapatalk

If it ain't broke, don't fix it. But at 170K I'd assume they'd need replacing soon'ish.

[Tip12345]

yes the rattle is a feature !
Here in Canberra mine has a rattle most mornings .
Just wait for a bit and away you go .

[Badger]

Hi thanks for the replies sorry it has taken so long to answer, I have been away for work. I had 2 glow plugs that were buggered and I replaced them all last night but unfortunately it hasnt fixed the problem. Thanks Brazilian Y60 I will jump.on that link and read what it says now. Also thankyou nissannewby, are u saying that there are 3 different solenoids that I need to check or is it one solenoid that does those 3 things ( coolant temp, injection pulse and timing control ). Thanks again

[Tip12345]

what part of the Country are you in . I think you maybee chasing a feature not a fault !
My pump was recently rebuilt . startup somtimes sounds like a few spanners loose ... when its -5 C
but soon changes . the control Advances the injection timing up when very cold .

[Badger]

In Tasmania mate, so yes it does cold but it shouldn't do that. I have a couple of other gu utes with td42t engines in them and although I had some trouble with one a few years ago idling rough and blowing lots of smoke on cold starts the problem was fixed when I replaced the dropping resistor that is a replaceable part that goes into the inlet manifold and had pump rebuilt at the same time. The other 2 utes I have are not the td42ti engine so they don't have the few electrics that this one I am having problems with now does, neither of them are intercooled either. Another interesting point is that the other 2 have the dropping resistor in the inlet manifold where the td42ti doesn't!!?? I know at least 4 other people with td42ti engines in their utes and they do not sound like mine does on cold days. It may not cause any problems by making the noise but I want to know what causes it or if in fact it is something mechanical that could lead to a very expensive engine rebuild.