Coolant Problem

[RDick]

After doing the cleaning of the EGR valve and cooler, plus changing the CCV filter and taking a long trip out West towing our 5th wheel camper, I noticed I was losing coolant from my recovery bottle. I see no leaks or the oil changing color. For the 4K to 5K miles traveled, I probably used 5 or 6, or more gallons of coolant. What am I missing? Is it going out the exhaust? Everything seems to be good and tight. I did have a water pump freeze up and I thought that might be the problem, but I am still losing coolant. Does anyone have a suggestion?

Thanks,
Ron

 

[BDaugherty]

If you already replaced the water pump and you arent seeing coolant on the ground or in the oil, then it is possible it is leaking from the egr cooler and being burned by the engine. Coolant is very bad for dpf's so have it checked out right away.

 

[mwilson]

I didn't want to be the first to say that.....a pressure test is next.

AND if it were my truck and the EGR cooler had developed a leak I would pop the pan and check the rod bearings after it was driven that far and digested that much coolant.
The Cummins may not be prone to this but I would still check the rod bearings.

It is a standing order at our dealerships that any EGR cooler failures on the Mercedes 900 engines get a rod bearing change along with the replacement cooler.
We lost two engines (one was in a parts truck of ours) that way before we figured out what was going on. They had both been operated for a while with failing coolers and make up coolant was being added on a regular basis.

Not trying alarm anyone, just a heads up....

 

[RDick]

Thanks for the reply's. Will pressure test, and why am I not getting any code's? You would think it would throw some type of code if it is
that serious.

Thanks again,ron

 

[Bob4x4]

If the egr cooler is leaking internally you can pull the egr valve and inspect. Water will clean the tubes and valve.

 

[RDick]

Will check the EGR after pressure test.

Thanks all,ron

 

[BLNRAY]

have done several ISL's that the cooler leaked on at least one of them filled the engine with coolant to the point it was coming from the turbo exhaust,couple oil changes and everything was ok.if you take the pipe,the exhaust pipe off at the cooler exit you can probably see wet places inside the cooler if its leaking bad,

 

[sag2]

If the truck was not losing coolant before the cleaning you may not have got all the air out of the cooling system. That little standpipe next to the cooler with the plug in the end is for bleeding the system after a refill. If it is leaking don't get too alarmed yet. Pull the EGR valve and the soot should be nice and dry. If it is wet or gooey the cooler is leaking. If the oil level isn't rising don't worry about the bearings. If you are concerned get an oil sample before doing anything with the internals.

 

[AnOldBiker]

I noticed my truck loosing coolant about 2008, two years after I bought it. Just slightly, but enough to concern me. I noticed it was when I was pulling a load only, but nothing under the truck when parked. Seems strange, but one thing I did was checked all my fittings on the hoses. There was a small hose that had a 90 degree bend and a silver wrap at the back of the engine, passenger side that had 2 hose clamps somewhat loose. I snugged them and refilled the level. Never had a leak since. Cheap fix. Have you checked the clamps ?

 

[RDick]

Thanks for all the reply's, will check, check and recheck and will get back when I find out something.

thanks again,ron

 

[RDick]

UPDATE: Well MWISON was right, had a pressure test done and with a lot of pressure a small leak was found under the small 90 degree hose from the EGR cooler to the head. Will check it under load when I head for Florida in November. Will let everbody know then.
Thanks for all the advise from all of you, the TDR came threw again.

ron

 

[mwilson]

That's good news and glad to hear it was an external leak.

Happy Motoring!!!

 

[RDick]

Update-update: drove to Florida approx. 550 miles, no leaks. Thanks to all TDR members for there help in solving this problem.

Thanks,again,ron