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Possibly not the head gasket?

20K views 14 replies 6 participants last post by  AK_Duramax 
#1 ·
So yesterday I drove my 2005 to work and it was running great. Then later when I got home my wife wanted to run a couple of errands and go to the grocery store. While driving I noticed that the heat was not coming on and the temperature gauge was staying on 160. We get to our first stop and my wife was just running in real quick so I sat in the truck with it idling. No change in temperature or heat. Then we get to the grocery store and when we get out of the truck there is coolant pouring out of the passenger side. I popped the hood and noticed that the overflow tank is full and the coolant is pouring out the overflow tube. As far as I could tell there wasn't any around the water pump or coming from around the engine. I was less than a mile from home and so after getting the groceries I drove home and the temperature gauge stayed at the 210 mark.

So this morning I went out to check the upper radiator hose to see if it was firm and it is not. So I am hoping that the overflow is from something else. Maybe a bad thermostat or the EGR cooler? I did have the water pump replaced about 4yrs ago.

Any help would be great. I am really not wanting to replace the head gaskets especially since I keep debating on selling this one as I use the 08 for hauling/towing now as this is more the back and forth/camping rig.
 
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#2 ·
Anyone?
 
#3 ·
Does sound like the head gaskets are bad-!! Most guys are in head gasket denial. Erratic coolant, pushing coolant out the overflow, are all signs of bad head gaskets. Sorry
 
#4 ·
Was the cap on the overflow tank tight? The entire system, including the overflow tank, is pressurized. A loose cap or a defective cap will result in boil-over and sudden loss of coolant from the overflow tank. A dealer should be able to do a pressure test on the cap and the cooling system.
 
#5 ·
So I took the truck to a local autoshop and had it pressure tested. They tried a block test a couple of times and it passed each time but the coolant is staying pressurized. The guy is not a specific diesel mechanic and thought maybe the EGR could be to blame but he wasn't sure. I found a local guy that is a diesel mechanic but only does part time work now. I am going to have him look at it and see. Thanks for JC1843 and P.Dog for responding.
 
#6 ·
The Duramax with a bad head gasket-- generally speaking--
--does not leak coolant in the crankcase, does not show with a coolant pressure test-- does not show with a coolant dye test.

Usually the top radiator hose will still show pressure [squeeze like a tennis ball] after driven hard- and sat overnight-- and before starting.
 
#7 ·
Could be any one of those things. Every truck reacts a little different when something breaks. Could be bad overflow cap like said that's not letting it de pressurize. Or the waterpump spun, bad thermostats, cracked egr cooler, I'd start with the cheap fixes first then go from there. HG can leak externally so look around the block for signs of cooling being pushed out.


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#8 ·
Sounds like head gaskets to me, have you had to add coolant recently? If the headgaskets are bad you will be having to add coolant if you haven't yet. What was the coolant level when you checked it in the morning after sitting? Have you tried cleaning the overflow tank Cap?


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#9 ·
If the pressure test is ok, is there soot in the coolant? If yes, you have a bad head gasket.
Have someone start the cold engine while you hold your hand in the exhaust stream. If the exhaust is white and tastes like coolant, bad h/g.
You can pull all the glow plugs on a cold engine ... if any are wet with coolant, bad news (h/g).
An internal h/g leak can be hard to find. It can leak combustion products into the oil, the coolant, or the atmosphere.
It can leak coolant into the cylinders or the oil. It can even leak between cylinders! Or, oil into coolant ...etc.
An unusually firm upper radiator hose on a cold engine is also a bad sign.
You may have erratic temperature ... going to extremely hot then back to about normal. It can display the same symptoms as a bad thermostat.
 
#12 ·
Loss of coolant, no heat and erratic temperature readings at times. Hard radiator hose was intermittent. I think the surest sign was opening the coolant cap. Normally you have a little pressure like opening a soda but with the bad hg it would spit coolant and air out under pressure for a few seconds.

The symptoms would sometimes go away for weeks at a time though if I was just committing and not working the truck very hard. Towards the end I put the overflow hose into a liter coke bottle so I could put the coolant back in the reservoir and see how much I was losing.

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#13 ·
So I had Trey (Blackdirtymax here on the forum) check it out and he says it appears that the HG on the driver side is the culprit. So its time to have them replaced. Any mods I should have changed while it is apart?

Planning on doing the EGR delete, shim the FPRV, and turbo downpipe. I'm debating on doing the exhaust manifolds also. Would it be worth it to do the dmaxstore up pipes and exhaust manifolds or just go with an LML driver side manifold? Any other things to change or improve upon? Truck is mainly a daily driver/tow rig.
 
#14 ·
So I had Trey (Blackdirtymax here on the forum) check it out and he says it appears that the HG on the driver side is the culprit. So its time to have them replaced. Any mods I should have changed while it is apart?



Planning on doing the EGR delete, shim the FPRV, and turbo downpipe. I'm debating on doing the exhaust manifolds also. Would it be worth it to do the dmaxstore up pipes and exhaust manifolds or just go with an LML driver side manifold? Any other things to change or improve upon? Truck is mainly a daily driver/tow rig.


Down pipe and manifolds, at least drivers side may be worth something to you. I would say it depends on what you do with the truck and what you plan to do in the future. I recommend grade C gaskets of course and ARP head studs. It all depends on how much you want to spend on it also.


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