Worn camshaft?

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Originally Posted by bee utey

Your backfiring is probably due to an exhaust leak at or near the head. Nothing to do with timing. It will suck air in on trailing throttle. Probably the engine noise too, as it is consistent with one cylinder firing. Do the garden-hose-stethoscope trick and try to pinpoint the noise. Probably a cracked or damaged exhaust manifold.

A useful tool for finding exhaust leaks is a strip of paper about 1cm wide 5cm long, hold it in long nose pliers or tack it to a dowel, hold it all around the exhaust joints. It will flutter where there is escaping exhaust gas. Saves burning fingers.;)

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Hi there, thank you for your reply. I checked for an exhaust leak (between the manifolds and engine block) and found nothing! The trick with the paper is a good idea, however I wasn't able to find anything. Tried also the garden hose trick. I have replaced the y-pipe gaskets already and will try to replace the manifold gaskets to be 100% sure.

I checked also a fuel pump and it delivers 165 litres/hour when the tank is full. However, with 40% tank the fuel flow is only of about 65 litres/hour and the pump picks up air! This could explain the loss of power (when I use more and more fuel in the tank). Seems to me that the one-way valve is stuck or something like this. I will look at it. The thing which I learned from this is that at full tank the fuel pump works sort of ok, therefore it doesn't explain the backfiring in the exhaust. I checked also injectors and they work perfectly. I can exclude fuel delivery.

I found also one interesting thing: my ECU doesn't detect misfire!!! I unpluged a spark plug wire, the engine started to run on 7 cylinders which was very obvious. Even tried to rev up to 2000rpm, however there was no misfire code stored in the ECU. Why??? Isn't the CKP or CMP acting in a funny way? Maybe thats why I have the timing issues. Any thoughts???

Thank you for any help! Regards J

Does anyone have any advice where to start and what to check regarding the misfire (non)detection? Thank you J

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Originally Posted by jiri_j

Does anyone have any advice where to start and what to check regarding the misfire (non)detection? Thank you J

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I doubt the D2 ECU has misfire detection. Unless it's mandated for a particular market it isn't fitted. It takes quite a major fault for the D2 check engine light to show. Australia go the full requirement for OBD2 quite late in the piece, way after the D2.

The D2 is OBD2, or I hope it is. Otherwise my scanner is working by art.

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Originally Posted by clubagreenie

The D2 is OBD2, or I hope it is. Otherwise my scanner is working by art.

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D2 is OBD2 that is for sure mate. Beeutey's comment was that maybe for Australian market they didn't enable misfire detection. Just wondering why. In my case whatever I do to get a misfire, it is not recorded by the ECU. Does anyone else have the same experience?

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Originally Posted by jiri_j

D2 is OBD2 that is for sure mate. Beeutey's comment was that maybe for Australian market they didn't enable misfire detection. Just wondering why. In my case whatever I do to get a misfire, it is not recorded by the ECU. Does anyone else have the same experience?

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*This is only my thoughts so please read it as such*
I would have thought the ECU will only pick up faults in the injection system.
A plug or lead would only show as runing rich and then be compensated for.

Might have to go back to basics, plugs leads, cap, rotor, distributor base plate ect..
I know you said you you pulled each plug lead, can you do the same for the injectors with out doing damage?

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Originally Posted by clubagreenie

The D2 is OBD2, or I hope it is. Otherwise my scanner is working by art.

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As I said, full OBD2. I meet many vehicles with OBD plugs that are not fully operational in Australia. Up to about MY 05 I meet plenty that don't do all the things MY 08 cars do. If a manufacturer can save $5 a vehicle by not including something they will. When first converting D2's I was surprised at how many things wouldn't trip the check engine light. Now I know its an industry wide thing.

Just did an '08 Triton, and it had the misfire sensor, because I tripped it. The MY 04 one I did earlier didn't.

Hello everyone,

I want to update on my progress regarding a diesel-like noise of my V8. This happens when the engine is at rather low RPM with loaded engine; I uploaded a sample of the noise in the first post of this thread.

Except the noise, which is particularly pronounced when the engine is hot (using HPR10 - 10W50 spec), the truck runs fine but I can feel that the power is not the same as used to be before. The engine is also slightly pinging when using 95; no pinging using 98 Vpower.

I checked a lot of things, beginning with the management system - checked ALL the sensors if they are within spec using an oscilloscope, checked exhaust leaks and vacuum leaks by presurising the exhaust and inlet, found nothing. During my last two oil changes I found metalic chips in the oil. These are non-magnetic chips of size 1mm x 0.1mm, there were of around 20 of them, and around 50 much smaller metalic particles. I cut the filter and after inspection I didn't find any chips in there.

I took the sump off and started from there. I checked the conrod bearings and they seem to be very solid. I inspected the camshaft - couldn't see all the lobes - but still found two lobes with some wear. I took a few pictures of the lobes; it is also obvious that there is some wear on the lifters. Sorry for the poor quality of the images :-)

Attachment 36890

Attachment 36891

Attachment 36892

Attachment 36893

I guess that the wear will be only worse resulting in a lot of particles possibly demaging bearings and other staff. Is it a time for a cam job???

Also the timing chain looks stretched, allowing of around 1-2cm movement towards the centre axis of the gears. I could turn the crankshaft a few degrees without turning the cam, so I guess a proper timing is affected. The chain set was changed 50t km back. What is the service lifetime of the timing chain and gears??? Also couldn't find specs what is an acceptable tolerance for a chain tension. Anyone could provide this information?

Thank you all! regards Jiri

Holy crap Jiri,,,, it seems that this has become an epic mission for you.

You mentioned that you had non magnetic flakes in the oil. Bearing material is non magnetic.

I know that you said that you had the sump off. Did you removed the big end caps(conrod caps) and inspect them? I know that you said it is in the same timing at the camshaft but you have to consider that the a conrod is only loaded up on the firing stroke (once per revolution of the camshaft) which means that a conrod bearing with minor wear might only knock on the power stroke under load (one revolotion of the camshaft).

If it is only minor wear of a conrod bearing you would probably not have been able to feel it with your fingers on the bottom of the conrod cap.

Were the big end (conrod) bearings replaced 40-50000klm ago after you had you oil pres probs? Premature wear may have started at that stage and got worse over time. Conrod bearing wear is very common and occures quickly with low oil pres.

Valve train noises are usually there all the time and are not affected by drivetrain load. Drivetrain load is only on the crankshaft.

You noticed excesive play in the timing chain. Is there any marks on the timing cover were the chain may have been slapping on it. Although would expect this noise to change with engine RPM and not drivetrain load.

Did you replace the spark plug leads before or after your knocking noise began. Leads in the wrong order / place on a V8 can cause all sorts of grief. Loss of power,,,backfiring,,,,,and detonation under load (pinging/eng knock).

If that sump is still off I would visually check the bottom end bearings while its all apart.

Happy hunting and good luck:)

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Originally Posted by jiri_j

D2 is OBD2 that is for sure mate. Beeutey's comment was that maybe for Australian market they didn't enable misfire detection. Just wondering why. In my case whatever I do to get a misfire, it is not recorded by the ECU. Does anyone else have the same experience?

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Just re-read this thread after the reminder email.

I looked back over my notes of my rebuild saga and I had misfire codes poping up, they only refer L or R bank but they are there. Check engine light did not appear, this occcured with a blown head gasket, subsequent massive overheat and then liners.

As for the chain, I'd look at the double row chains, availble from TRS etc. Also if (when) you do replace the cam/lifters, the main attributor to wear has been discussed recently as being due to the use of low phosphates a and sulphates or something. What I do remember is that HPR Penrites are high in these but Brad Penn Green Oil is the highest I know of, it's deare but only because you have to buy it by the box from memory (US fl.oz sizes but a box will cover 2 fills and it's only around $10- more for a fill than Penrite.