Coolant system pressure issues
 

In need of some thoughts, coolant system is preassureing up and pushing fluid into resivore. Only when it idles and I get in and accelerate over 2500rpm. The coolant is around 145degrees before taking off. I've changed thermostats thinking that was issue, not the case. I have an h&s egr delete and am wondering if it is because of that style. Had system pressure tested to verify head gasket. Just weird. Thanks.

Is the coolant not returning from the reservoir? If so, it may be a faulty radiator cap.

No it's not. I replaced the cap and no change. But if I hold my hand on there it will draw it back into system. It's weird.

if the water pump and thermostat is working properly, they can be only the head gasket. here is a simple test you can do. let the truck sit over night after running. the next morning crack the rad cap. if they are big pressure there you have a head gasket leaking.:hellox:

But the system was pressure checked, and held up fine. I guess it is possible a head gasket would allow air into the coolant, but not coolant into the cylinders. It is interesting how head gaskets fail.

the 6.7 seems to seal back at low boost. at least that is how mine started. in my opinion the best test is the morning after. if they are big pressure there if can only come from one place:hellox:

With it being a closed system wouldn't it hold some pressure? I have a 16lb now but why won't it draw the coolant back?

it will have very little pressure if the head gasket is ok. as the temp cools down so does the pressure.

Head gasket. I wouldnt run the factory gasket again. I would install studs and run the vulcan head gasket.

I went to Vulcan performance and they sell a victor gasket. Is this what you were referring to?

no contact lazarsmith as far as i know you can only get it through lazarsmith not 100%on that but pretty sure. this is his custom gasket. here is his web site>>Si Vis Pacem Para Bellum

Make sure ya check the head over good.......we had a slew of bad ones at Kenworth

Just a little update, so I returned truck to stock and took to dealer. Dealer argued and said it was coolant ( due to blowing it out on road I poured in some green stuff ) and I said no. Done my research and that not it. So they ended up replacing the egr cooler ( which wasn't on the truck when problem arose ) and blamed it on that. Told me truck was ready to go. Pretty sure when I pick it up I will blow the coolant back out. Got a set of head studs all the same. Stay tuned.

:pca1: good luck

yeah it will blow it out :ouch:

Have you had it block tested? There's a tool available that you put a solution in, suck some coolant in it from the radiator, the solution changes color if there are combustion gasses present. I'd be surprised if the dealer didn't do it while you were there, but you never know.

Yes I did. I did it before I took it in. I also pressure tested the system and held like a rock. That's when I turn to the forum. No indication of gases in coolant. But after talking to some of the older more experienced mechs on here I could mimic the symptoms of bad head gasket. I did find out that dodge has some new shift programs for the non HO 6.7's.