Losing coolant but do not know where.

[Rawze]

This time of year is when these types of problems occur the most in engines as they age. ...

http://rawze.com/forums/showthread.php?t...67#pid1267

http://rawze.com/forums/showthread.php?t...05#pid1105


I have had at least 5 other people in this past month alone that have had coolant loss issues that ended up being the head/head gasket in their engine. The bulk of people I have spoken to this year that have had this problem actually do NOT have the "mandate removed" or any other type of custom mods to their trucks. They have totally stock engines. There have also been a few with moded and/or deleted engines have this problem too. It seems to be a trend every year with mostly the CM871's and CM870's with more than 500k miles on them, and it happens as summer approaches. It does not point to anything specific, but I can tell you that it is common in engines that have suddenly run cold at some point, or in engines that have been overheated in their past. it is also most common to see it between cylinders 3-4 or 4-5, and that it is not unusual to find the head bolts a bit under-torqued in that area from the factory in CM871 engines. Speculation is still out on the under-torqued bolts being caused by the leak itself, or if they were like that to begin with. Personally, I think all the head bolts on CM871's from the factory are under-torqued that reside under the cams. You can just tell it when you use the method for torquing them from the service book and you use a wrench instead of an air-gun. The +90 method should realistically be about 130+ on only those bolts. Tightening them by hand reveals the differences easily as you tighten them to their final resting place.


I had someone 4 days ago come over here and had theirs checked out to see if it was the head or egr cooler. He was convinced it was the EGR cooler, and thought a egr delete was the way to fix it instead of buying a new cooler. Head was leaking so bad it was blowing soot into the coolant tank. The guy was asking some advice on someone who could remove the govt. mandate, but -- It clearly was not the egr cooler. It was the head and his truck only had 520k miles on it. I felt bad for him. You could tell he just didn't have the money to get the head replaced, and he had just purchased the truck 3 months earlier with no warranty on it. ?He said he had already been looking into getting the truck "dlted" a month earlier ... I looked at him and told him that if he had done that a month earlier, he would have been directly accusing the person who did the work.

I would start by pressure testing the system, etc. and eliminating the usual suspects like the air compressor, turbo, etc. then go from there.

Since you have the ",mandate removed" , just ensure you have good programming too. Check your turbocharger position at idle using Cimmuns Insite. The "VG Position Measured" should be a low position like 5% or maybe 15-18% max at idle. If it is a high number like 45% or higher, then you have bad programming too. Also, your boost should never exceed 38-39 psi for that CM871. if it does, then it is over-boosting, and if it is above 41+ psi, it can be damaging to the engine.

Every engine with any type of non-factory tuning should have a boost and pyrometer gauge in them so things like that can be spotted, and to also help the driver save fuel etc.

Just my own thoughts on it -- Rawze