head coming off again

[Andre Steyn]

Well as things are currently looking I'm going to have to find someone reliable to do the setup for me. I nogal spoke to mynardt over the phone today and I mailed him the pics and he said fueling caused my problem. So I honestly don't know anymore. The only other thing that I can think of is that the faulty head gasket caused the water level to fall very low and that the moter did infact overheat. And the sleeves got scorched before the pistons did. I did have to top up the water considerably at one stage but nevet had a severe temp reading.

[Andre Steyn]

Hows your egts and power now??

[Peter Connan]

Well as things are currently looking I'm going to have to find someone reliable to do the setup for me. I nogal spoke to mynardt over the phone today and I mailed him the pics and he said fueling caused my problem. So I honestly don't know anymore. The only other thing that I can think of is that the faulty head gasket caused the water level to fall very low and that the moter did infact overheat. And the sleeves got scorched before the pistons did. I did have to top up the water considerably at one stage but nevet had a severe temp reading.

The water temp sensor sits in the highest point in the cooling system. As a result, if the water level is very low, then it does not accurately reflect temperaturs in the rest of the system. So this could be the problem.

Fuelling might also be a problem. I don't think that ignition is happening at the wrong time, as the score marks are the whole length of travel, but possibly if fuel is delivered all the time (leaking injectors/pump) then it could be washing the oil from the bores?

[Andre Steyn]

I think the pump and injectors are becoming more and more suspect, but now the million dollar question rises, if infact they are what are the correct pump volume settings per injector and the correct crack pressure for the injectors cause now honestly I'm going to have to check everyone doing settings for me!!! And the other thing who do I go to now?

[ricster]

I presume you have a Zexel Pump with aneroid ( or whatever that thingy is called ). Bosch Diesel workshops should be able to check, setup and/or repair the pump to spec. Which one?..... not sure mate, but Bosch are a big brand and should have the proper training. If I am not mistaken Bosh are Zexel Agents.

Do you know anyone in the transport industry who could maybe recommend a specialist in diesel pumps?

My EGT's are a bit high, but just never get the time to send the patrol in for a fine tune, as its my daily drive. That said, I have great power from this beast.

[Andre Steyn]

Jip zexel pump, I used my pickup td42ti fuel pump specs last time we did it, seems like that was a mistake!! I know a few guys in my area that are actually zexel agents but. But with the issue I have now I'm not sure who to talk to! As for the big transport guys I know a bunch but 90% of them go to gauteng to sort there fuel issues. Cedric can you remember wat boost you're running?

[Andre Steyn]

A very interesting thing I've just noticed while flipping through the fotos is where the head gasket was blown on all six cylinders its exactly under the precoms under which the bore scoring has occured. Do you guys think this is actually my main issue?? Maybe a severe loss in compression on that side, or an increase due to the water or air drawn in at that corner?

[ricster]

I don't have a boost gauge unfortunately..... working on a new mold that will fit on top of the existing dash, that will have VDO gauges in ( oil pressure, oil temp, water temp and boost ), as my EGT gauge only has 2 EGT temp (pre and post turbo) ports and 2 cylinder head temp ports.

So to answer your question, I was told that the boost setting is set at 0.5 bar. I believe that even on the "black" top TD42, you can comfortably boost up to 1 bar MAX with the correct fuel delivery settings. You will have the correct type of pistons and rings for the turbo to do this, as well as oil squirters ( make sure the oil system path for the squirters is clear and oil does flow through the WHOLE system).

I'm wondering if there is maybe a problem from when they machined out the sleeves before honing them that some metal shavings/pieces got into the channels that feed oil into the squirters and either blocked or restricted them, or even got forced through to the oil rings and settled between the rings or somewhere between all the rings. Will be difficult to see the cause on the piston side but would show up on the sleeves. I'm just trying to find possibilities of why it happened. The two materials would be the same so the shavings/pieced would wear away to nothing whilst leaving there marks on the sleeves.

Maybe for piece of mind try this. With the squirters fitted to the block and a BIG syringe with some rubber tubing, pump oil back through the squirter and see if the oil comes out the block somewhere. This should flow easily with little resistance. This could also be a cause for the scoring of the sleeves if there wasn't oil flowing freely onto the inside of the piston and splashing out onto the bores. Maybe even a good air blast to ensure the channels are clean and free of ANY material.

[ricster]

Are the precoms flush with the head? They must be 100% flush if my memory is correct

[Andre Steyn]

They are actually at the factory spec of -0.05 cause I had to replace the head the last time I did the machine. I'm also suspecting oil supply, but according to the enginering oom if the squirters where blocked the pistons would have seized stuck in the bore! I was also,running .5 boost, I really need to get a proper egt setup! Especially after this mess! Clearly what I had was rubbish!!