My friend has an 01 Dmax.....daily driver and tows horse and cattle trailer on weekends. Has 137,000 miles on it and had injectors replaced last year. New issue is that it wants to cough up or spew out some coolant when towing the trailer. It doesn't do it with daily driving, only towing. Coolant temp gauge is never showing hot and it doesn't seem to be over heating. Low coolant light will come on and add a 1/4 or so of a gallon and all is well, until the trailer is hooked again. I can take cap off and there is always pressure on it, even after sitting for a day. The mechanic said it was producing some sort of gas or something, as he could tell the overflow tank was swelling ( I dunno)......anyway, he also said it may be a head gasket starting to go. Does any of this sound right? He said he had never seen one of these act like this and really didn't know where to start, without just tearing it down and checking. Any thoughts or ideas on where we might need to check. He said drive it until it really shows itself or something fails and then you will be able to find the trouble. Thanks for your time....!!

after they got done with my injectors and new head and alot of other things i got my truck back and mine was doing what u say building pressure and if u took the cap off it was a bad thing stuff every were so i took it back and come to find out that the antifreze was going into the block from a bad new head from gm ..............so if i had to guess i would say it would be a head gasket going bad from my experince

bad head gasket just had mine done at 120000.

The first thing I would test is the Radiator cap Pressure and vacuum, them take a bottle with soapy water in it and put it on the surge tank outflow hose after the system is hot then drive it loaded up a hill and watch for bubbles on a class eight you have to run the engine for three fan in cycles to check for head gasket problems as it will blow out air until it normalizes. PLAY SAFE!

what is the going price for head gasket replacement?

I own a 2001 lb7 mine is at the dealer now getting injectors and possibly new head gasket they tell me between 3000 and 3500 dollars. Today the news was that it might be a cracked head. who nows what this will cost.

Also, the cap was replaced last week and it might have helped a very little bit, but not cured from it.




The first thing I would test is the Radiator cap Pressure and vacuum, them take a bottle with soapy water in it and put it on the surge tank outflow hose after the system is hot then drive it loaded up a hill and watch for bubbles on a class eight you have to run the engine for three fan in cycles to check for head gasket problems as it will blow out air until it normalizes. PLAY SAFE!

Possibly a cracked injecter cup. I'd look for that before lifting the head!!:D

OK, I'm gonna ask........how does that relate to coolant issues? I'm still trying to learn these diesel engine problems. Thanks!







Possibly a cracked injecter cup. I'd look for that before lifting the head!!:D

01-02 had head gasket issues.......thats where the problem lies.

The fact that your friend had the injecters replaced last year got me thinkin'.....it reminds me of my issue.( An incorrectlly installed inj. cup was my culprit.) The symtoms were similar to yours. I'm not sayin' it's for-sure.......just a poss. that is easier than the gasket.
(Coolant flows through the head, around the inj. cups.) Good luck, Ed.

Thanks for the help guys. He is all tore up about it......you gotta do what ya gotta do though. We'll see what is is before long I suppose. Thanks again, Brad

I had injectors replaced by an incompetant mechanic who did not put seals on the injectors. Resulted in low coolant light and similar problem. Also it was blowing vapor out the crankcase and put coolant in the oil. I had the vehicle towed to another dealer where they replaced the broken injector and reinstalled the bad ones. They ended up finding out that the head had been damaged in the process. Final cost $6000. The head was $701.00 Not fun. Now the truck is blowing white smoke again.

I went throught head gasket change and new heads, removing injector cups, have mechanic find the two lines that feed coolant through the turbo and close them with vise grips,my 03 was pushing coolant out under boost(over 20 lbs)it wouldnot lose coolant under normal dirving ,just under trailer towing(44 ft enclosed goose)

jim4x,

So was your truck loosing coolant thru the turbo (and not the head gasket, injector cups, etc)? Maybe the coolant lines were leaking (there have been reports here about that).

Also, how can you just close off the coolant lines, it seems like the turbo needs the coolant flow to cool itself?

FLYIN99----

Had this same exact problem. Replaced overflow cap, no luck. Did many searches and asked many questions on here and called around to dealers, everyone said head gaskets are going bad. I was at a local auto parts store and came across a product called "Nanotechnoligy Head Gasket and Block Repair" . Decided for $50 it was well worth a try. Followed the directions to a "T", and actually left the truck sit for 24 hours instead of 12 like the bottle said. Flushed the system and installed 2 new thermostats and filled er up with coolant, and 2 this day. . . (knock on wood) NO PROBLEMS.

This process will take about 2 days to complete as you MUST get all coolant out of the system. I think it took me about 15 times to flush it completely. Well worth it in my experience though. Ive drove the truck hard since day one, and have continued since ive used the repair. . .

If any of you guys out there would like to get more info on this product, let me know. We are currently using it on a BMW 325is with a blown head gasket. If anyone wants to try it, and cant find it locally to them, id be more than happy to send some out to ya as $50 is a lot cheapper than the $4000-$6000 qouted for the repair.

I think a discussion with the people involved in the injector replacement is the thing to do and let them check head gasket issue.They were the last ones there.

I've read enough on here to know that it's not that hard to mess those injector cups up when replacing injectors. How many miles since injectors? That would be the first place I'd start, if it is the cup then they should cover the cost because they screwed it up. Don't put it off too long and crack a head. JMHO

Truck is a dealership.........they did some tests (whatever they do there) and said it was in fact the driver side head gasket. 2 days have gone by and the fenders and such are off the truck and they have it torn down. They said it must have been bad for a long time, as one of the head bolt was corroded extremely bad they said. We'll see. They were trying to explain the A, B, C head gasket thing, but whatever.........just fix it. Let's wait and see. Thanks for your alls help and information on this!!!

Brad

my truck was pushing coolant out the coolant tank under hard boost,not out the turbo,we closed the lines in and out of the turbo and ran it hard once or twice,no coolant loss,we had already changed heads,and gaskets,used ARP studs,then pulled the inj cups as per advice of one mechanic,still pushing coolant out under hard boost,changing the turbo and no coolant out of the coolant tank.
So was your truck loosing coolant thru the turbo (and not the head gasket, injector cups, etc)? Maybe the coolant lines were leaking (there have been reports here about that).

Also, how can you just close off the coolant lines, it seems like the turbo needs the coolant flow to cool itself?[/quote]