Chevy Venture 3.4 Dexcool Saga

[mechanicx]

Originally Posted By: Colt45ws
Yeah, but these vans don't have a pressurized reservoir, either.


Right, but they don't have iron heads and a non-pressurized reservior which is the worst combination. Wel lthe 3.8's did but that's a different story lol. I know the vans and and the cars based on that platform don't have a pressurized reservoir, just the ones I listed the ones had a pressurized reservoir. I don't totally trust dexcool in the non-pressurized reservoir applications.

 

[Zedhed]

Originally Posted By: mechanicx


I don't totally trust dexcool in the non-pressurized reservoir applications.


I don't trust Dexcool in ANY application -- that's just me however....

 

[Trav]

Looking at these LIM gaskets there isn't much of a seal there,the thin rubber seal around the ports is shrivelled.
The new felpro steel have a massive sealing area,it looks like they would seal under the worst conditions.

The other rubber seals i.e. thermostat seal and water pipe orings remain in good shape leading me to believe maybe GM used inferior material,not enough of a seal or both.

Regardless the best gaskets wont fix the sludge issue associated with this coolant.

 

[Robb235]

Yeah, I would switch over to the green stuff and ditch the Dexcool.

 

[eljefino]

Originally Posted By: AuthorEditor
Coincidentally, I spoke to a local used car dealer (who has a decent reputation) a couple of days ago who was telling me to never touch the Venture or the Montana because of the difficulty of working on that engine. His opinion, for what it's worth, was that the vans are more prone to the IMG problem than the cars, for some reason.


Probably because the vans get sent to auction not repaired at the trade-in dealer because it's such a pain.

If you can monkey around the rear bank of these things and not invent new swear words, you've found your calling.

My 97 silhouette ran me 300 bucks with a dud injector, was stuck open and flooding everything out.

Onstar has a monthly email update on the newest stuff with % oil remaining on the OLM, and they can get trouble codes. Would not be a stretch to have you get the emails, except for programming and willpower to not have a dealer be the go-to outfit.

 

[1 FMF]

haha, i plotted a graph on here a year or two ago when I had used fuel power i think it was called, for quite a few miles and showed zero noticable improvement. You could bottle [censored] and sell it as an engine cleaner and no one would ever know because 99.9% of people don't tear into a motor.

i agree that no fuel additives are needed, especially if the engine is running well and not burning oil. Those commercials, which i think are shell's, of showing buildup on the backside of the valves is complete b.s. it does not happen.

the whole synthetic oil requirement is also b.s. the deposit you had noticed i would argue might be more from the overheat conditions, and if the engine never had an overheat problem you probably would see less deposits.

the overheat condition is not solely dexcool's fault, it is from complete neglect and zero maintanence of the cooling system. If you never change the transmission fluid and the trans [censored] out at 110k miles, is it necessarily the fault of the transmission fluid? Given the cooling system neglect, I would get a good caustic cooling system cleaner prior to refilling.
And since you got the heads off, look at the cooling ports in the heads,intake, and block and see if there's evidence of erosion especially on the intake manifold gasket.