2004 Montana cooling issue

[SKroads]

My coolant gauge is usually like the first image. Lately, especially after driving on highway and slowing down to in-town speed or if stopped for awhile, sometimes spikes around to what the second image after I restart my van. This issue has started up within the past 4-6 weeks.

Usually, I find my coolant tank is down a little when it happens. I pour some coolant into the tank and the gauge goes back down to normal for awhile. Coolant does seems to get eaten up slightly after highway driving. No sign of a leak underneath.

Earlier in month, I have replaced my thermostat with a new failsafe version and had a flush. Also it passed a short pressure test. Heat appears to be still okay, although it doesn't heat up fast at low heat settings. AC is fine. Also, a cooling fan sensor was also replaced. Radiator appears to be fine.

I plan to have it checked again with a full pressure test. Not sure what is causing it this issue.

 

[melsg5]

I recommend you also have a coolant hydrocarbon test done to check for internal leaks

 

[SKroads]

Test was positive for hydrocarbons

Looks like it is the head gasket. Got the estimate and it's a $2500.00 fix and 2-3 days downtime.

 

[melsg5]

you got the estimate from a dealer or private shop? did you shop around for a better price?

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[EaOutlaw]

Yeah I know prices have changed considerably since I was in the business but I remember I nearly restored a customers v6 chevy s10 truck with a re manufactured ATK engine,
All new belts and hoses, radiator, new injectors, shocks, brakes, clutch motor mounts and countless other things for about $3500 parts and labor.

Recently I was quoted $350 for just a transmission service on my wife's HHR

I guess the dealers and service centers are sure proud of their work.

Too bad our income has not raised up with auto repair prices.

Good luck on getting the work done, regardless of who does the work make sure they address the original problem and have them replace the entire cooling system water pump radiator hoses etc if necessary or any if these parts are original.

It would be not so smart to pay these people to remove and replace a part that could lead to the same problem down the road.

The shop would just tell you, sorry that newly failed part was not part of our original quote thus not covered by their warranty.

 

[SKroads]

Estimate was work on the heads by a machine shop, kit updating the gasket, valve replacement, and labour.

I found out there was a brown sludge paste of some sort inside when they were pulling out the cylinder heads, and it likely made fluid in coolant tank red. No additives were ever added to the coolant.

Did have a transmission flush a few months ago.

They did mention the heads were very badly pitted when they were being sent off the the machine shop during repairs. Was without a vehicle for 3.5 days when repairs being done since it took a lot longer for the machine shop to finish the work.

After getting repair done, drove it for over 2000km before an overheat issue occurred again, but this was while driving at under 50km/hr in a town. This time, the thermometer went into the red zone. Had to go to the local Canadian Tire to buy some Prestone.

Work was done at a shop, no way I would go to the dealer. Other places have higher labour rates. I know it was 12 hours labour.

Currently trying to find out what is causing the overheat problem this time. Also does anyone have any idea what the brown sludge paste could possibly be?

 

[SKroads]

Entire cooling system? Including the block?

I know up here, a transmission service to pull it apart piece by piece was about $500-550 and that was a decade ago. Likely much higher now. Labour prices have spiked quite a bit some 5-7 years ago in my area. Remembered a time when rate was $30-40/hr, now finding much under $90/hr is hard for a good place.

Yeah I know prices have changed considerably since I was in the business but I remember I nearly restored a customers v6 chevy s10 truck with a re manufactured ATK engine,
All new belts and hoses, radiator, new injectors, shocks, brakes, clutch motor mounts and countless other things for about $3500 parts and labor.

Recently I was quoted $350 for just a transmission service on my wife's HHR

I guess the dealers and service centers are sure proud of their work.

Too bad our income has not raised up with auto repair prices.

Good luck on getting the work done, regardless of who does the work make sure they address the original problem and have them replace the entire cooling system water pump radiator hoses etc if necessary or any if these parts are original.

It would be not so smart to pay these people to remove and replace a part that could lead to the same problem down the road.

The shop would just tell you, sorry that newly failed part was not part of our original quote thus not covered by their warranty.

 

[SKroads]

Found out that the body control module is not sending the right signal to the cooling fans. Currently the quick way to override the problem is change fan setting to defrost or turn on the AC. Only thing extra I was charged for was a new rad cap. Water pump appears to be fine. Was mainly more downtime than actual cost so far.

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[EaOutlaw]

Fix the cooling fan asap the one day someone drives your vehicle and forgets about keeping it on defrost is the day you will find out that the engine gets cooked again.

When I suggested upgrading the cooling system I meant to have any cooling system parts that were easy to change while the head gaskets were out.

That was the time to get the extra work out of them free or much cheaper.

Now since you did not have them do the extra work, if one of these hoses develop a leak and you blow a head gasket again they will blame the hose
or part and charge you all over again.

No I did not suggest replacing the block

The sludge you found was most likely a combination of old coolant and chemicals that came out of solution from someone not using distilled water in the cooling system

The pitting in the heads will also contribute to the sludge as some of the sludge was aluminum and cast iron also that corroded because of a non maintained cooling system