Coolant leak

[kvfmechanic]

Hi
I have a 2001 Silverado 2500HD with a Duramax.(255,000 kms) In the past 10 months or so I have developed a mysterious coolant leak that has gotten slowly worse. I am guessing it is internal( head gasket or injector sleeves) but am wondering about symptoms. I am not getting any noticeable white smoke or bubbles in the cooling sytem. The injectors were changed 2 years/ 70,000 kms ago by a dealer with not much duramax experience. The system seems to be holding pressure fairly well as I can go back an hour after shutting it off and still have lots of pressure when I take the cap off. ANy suggestions? Thanks

[Mark Rinker]

Most likely head gaskets. 2001 production year is known for this failure - gaskets were improved and updated in subsequent years.

Search elsewhere on the forums '2001 head gasket' and you'll see the trendline.

[tx dave]

I agree with MR. I went through what you're going through. If the pressure is high (hard upper hose) after an hour. Pressureized system when you take the cap off, bubbles in the tank (hold a flashlite to it) and you'll see them. YOU HAVE A HEAD GASKET LEAK. Been there done that. I ended up changing my engine. I have an 2001, love it and will keep changing engines out if I have to until I die or wreck it. Love that truck. it still runs like new, looks like new and when I tell people its an 01 they can't believe it (Its still shiny and pretty). But yea, you're getting a small head gasket leak. I use to put a plastic bottle by the overflow tank to catch the anti freeze and pore it back in the engine every morning. Good luck with it.

[phillipokc]

I had a similar problem, ended up being the oil cooler gasket.

[More Power]

Under normal circumstances cooling system pressure should be practically nill when the truck sits for 12 hours or more. If there's a whoosh when you loosen the coolant surge tank cap, there's more pressure being generated than normal. Even though these caps are vented to limit cooling system pressures to 15-psi, chronic overpressure usually results in water pump seal failure. Now, you've got two problems....

Jim

[9365turbo]

That's what my 02 gmc was doing. I replaced my water pump first and had coolant blowing out for a year. I took the plunge and replaced the head gaskets in february. No problems since then.