2000 Trooper leaking coolant

I have been unable to determine the root cause of my 2000 Trooper (96K miles) leaking anti-freeze; about 1 gal per 5K miles. The dealership has done the pressure tests and check of the heater core. There are no deposits on my garage floor. When I suggested the loss could be absorbed in the engine, the dealership advised me to look at the exhaust, would be whiter than normal.

Does anyone have any advise on where to go from here? Although I have 24K miles left on the power train warantee, the dealership is not going remove the head without probable cause.

One last question - should I consider adding one of the stop leak products to the radiator? Naturally the dealership does not advise doing this.

I would contact your area Isuzu service writer and let them know about your problem (Call Isuzu corp to find out that info). The next step would be to head to your dealership weekly or monthly (I hope this is an option for you), so they are document the amount of water it is using. 1 gallon every 5k is not acceptable. I would hope Isuzu would treat this like the oil usage problem (use more then 1qt per 1k you get a new engine).

Your dealer should beable to do a leak test on the head without removing it. I think this is done by screwing in an air hose into the spark plug hole. Then I think they can see if there are bubbles that come up from the radiator fill hole.

Thanks for the suggestion Amigo-2k. I took the Trooper to the dealer this AM. They were great, they brought out 3 techs to discuss between themselves what the issue could be then alas they removed the PCV valve and found a white coating which meant the coolant is mixing in with the oil. They want the Truck for a week to dig down deeper, remove the head, etc. Luckily the 120K powertrain warrantee is in effect.

Good stuff! I'm glad I have my 10yr/120k too!

Thanks for the suggestion Amigo-2k. I took the Trooper to the dealer this AM. They were great, they brought out 3 techs to discuss between themselves what the issue could be then alas they removed the PCV valve and found a white coating which meant the coolant is mixing in with the oil. They want the Truck for a week to dig down deeper, remove the head, etc. Luckily the 120K powertrain warrantee is in effect.

Good for you ED!! Keep us posted on the outcome. Head/head gasket issues are far & few between on these engines. Hopefully they'll get you fixed up ASAP, as coolant in the oil will destroy an engine in short order. I'd get a used oil analysis done (try bobistheoilguy.com) to get something on paper now- as to the condition of your engine's internals. Also keep an eye on your oxygen sensors & catalytic converters, since burning coolant destroys those as well. You've got about $1500-2000 alone in O2 sensors & cats on this truck. I'd bring that up (as diplomatically as possible) to the dealer as well!! Keep us posted!

G/luck
Joel

Excellent advise Joel! There may indeed be longer term issues for me going forward. Today's diag was written this way. "Found evidence of coolant leak, possibly internal at PCV valve. No coolant present externally, no coolant in ignition plug holes. Recommend disassembly and will probably need LH and RH cylinder head and/or gaskets.
The lead tech advised me the 2 previous pressure tests I had done cannot detect leaks reliably. I wish the previous tech who worked on the truck realized this rather than giving up so easily. I'll update again around Feb 1 as the truck will be there from Jan 24-29. On a separate note as I questioned Isuzu's commitment to us Trooper owners to the service manager, he commented he has had good luck with Isuzu honoring warrantees and he thinks Isuzu is looking to get out from under GM? and re-introduce the Trooper/Rodeo. We'll see .... Ed

For those following this thread, the dealership found the right bank cylinder head was cracked and leaking. The replaced it and all the related gaskets (10) and also replaced the left valve cover gasket that was removed for diagnosis purposes. This was all covered, 100% under the 120K PT warantee. The dealership estimated the work to be around $2K.

Nice, I'm sure you are glad you bought it new in 2000 now!