[zman111]

I am baffled at my problem and I am looking for some help....
I have an 05 6.0 cc/sb with a little over 120k on it about 15 months ago the dealer had replaced the head gaskets,head bolts, egr, oil cooler and the rad.
truck runs fine no puking, no coolant loss at all. The ECT is always between 186 and 192 the fan cycles on and off when it needs to, however the EOT around town is always 205 or a bit higher, on a road trip the EOT can climb as high as 225 now heres another kicker around town I dont get any heat but if I am driving down the highway at 70 mph I get heat! :dunno: I have flushed the system with VC9 and all I got out was a "honey colored" fluid. I really dont think I have a clog or that the oil cooler is bad I am thinking a bad water pump? maybe a bad heater core? maybe a bad oil temp switch?

thanks for any and all help!

 

[ImaPoser]

Based on the part about no heat around town, check for a bad water pump/impeller. Poor coolant flow could be a cause of the other issues as well.

 

[zman111]

Yeah I am thinking the same thing. I guess there is a chance the heated core could be blocked? But I have been told that these trucks could have a bad water pump and still never over heat?

 

[forddieseldoctor]

Disconnect both heater hoses and hook up the garden hose backwards and flush it out.

 

[zman111]

I will try that thanks

 

[Lilpooh]

Disconnect both heater hoses and hook up the garden hose backwards and flush it out.

Make sure you have another hose hooked up to the other line, and make it exit to the ground, or else you might get a face full of coolant.

 

[forddieseldoctor]

I usually unhook the one from by the alternator and the other one by the degas bottle leaving the hoses on the heater core.

 

[zman111]

a blocked heater core wouldn't give me high EOT readings would it? That must be from a bad water pump?

 

[2 stroker]

a blocked heater core wouldn't give me high EOT readings would it? That must be from a bad water pump?

It may be from all the casting sand running through the motor and cutting away at the water pump about the same as a jet pump on a boat :dunno:
2 stroker

 

[nylyon]

The heat in my truck was horrible as well. I suspect (now that is) that the EGR cooler plays a role with the cab heat. The coolant travels from the water pump through the oil cooler, then EGR cooler then returns to the same area in the engine where the heater core picks up from. Good engineering point to help build cab heat faster in the winter, but if the oil cooler is clogged, there won't be as much hot coolant into your heater core. It seems that you are walking down a similar road that I had traveled. This post documents my trials with the oil cooler, the water pump route and the oil temperature sending unit route. Not that it can't be anything else, just read through, there's a lot of good information included in there and it will give you a better understanding of the oil cooler in general.