Thick oil

[PeteMelb]

Hi names Peter, I’m an ex driver now mechanic in Oz I look after about 16 trucks and 13 trailers.

I’ve learn’t many things from watching the videos and reading these forums and I thank you for the chance to participate.

I like to do things myself but now I have a strange problem and I’m wondering if anyone else has seen or heard of this happening? and possibly able to help with some ideas.

But first some background.

One of the trucks I look after is a 2007 International Eagle 9100i with an EGR ISX engine, this is an old motor and has done over one Million Klm, its serviced every 20,000klm and runs excellently, it has a few oil leaks but for an old motor it runs clean and pulls well.

Due to the cost of another header tank, for the past few months we have been fighting to stop a coolant leak from the level sensor located in the plastic header tank mounted on the radiator.

The truck used a bit of oil between services but nothing I wouldn’t expect and it did use a lot of coolant due to the what I believed to be the header tank leak, so after deciding to just purchase another tank I replaced it last service.

The driver/s failed to report for sometime that they were still topping the coolant up everyday up to 4 litres even AFTER the new tank was fitted.

So I pressure tested the system and found 4 external leaks at various hose clamps but not nealy enough for 4 litres a day, I checked the EGR and pressure tested the EGR cooler (as per Rawze’s video) and it was dry and no visible leak, I checked the exhaust behind the turbo and it’s dry, and no leaks this truck tows a white fridge van everyday and has no DPF so if it was spitting thru the pipes the van would be black by now and as I said earlier this truck runs very clean, the van isn’t even sooted.

As the truck was almost due for a service I dropped the oil only to find what came out was a very thick very very black Goo the filter was also clogged with this very thick oil. I decided to take the rocker cover off and found that most of the rollers were just starting to loose there hardness so I’m fixing that.

We use 200 litre drums of Valvaline Oil and have done so for years without any problems, and Valvaline have come and collected a sample of the oil already but no answer until next week.

Now finally to the problem:

The truck needs to work and I’d prefer to start fixing whats needed, I believe the oil is contaminated with coolant that has evaporated the water from it but I can’t find out from where the coolant entered.

I have the sump off and the water system pressurised to 15psi and left it overnight and nothing, I have no problem replacing coolers or even liners if need be but could I be missing something simple??

I’m going to drop some bearing caps in the morning to see what they look like but I’d like to know exactly where this coolant is getting in from before i start pulling things apart.

PS: I apologise for the length of my first post but I understand the need for detail when trying to diagnose blind.