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I have a 2002 year end (2003) Pontiac Montana, its AWD.
It has 138,940 on her.

I bought her two and a half years ago for $3200.
This thing had one previous owner and she used it as a Yoder-Toter. (She hauled the Amish to stores and what not).

She was my buddy haul'in late night summer fishing trip vehicle.

Okay enter my denial:
And this winter in Ohio we had -20+ temps. One day the wifey was taking her to work and she decided to not put
out heat. Well I thought it was the thermostat again. (I replaced it when I first got the van.)

I replaced the thermostat. Then I got a coolant flush at Valvoline.

They burped the engine. Then I noticed I still wasn't getting any heat.

Then I noticed when I accelerated the gauge would fluctuate and then drop to normal and then Id get heat.

Well I replaced the ETI(?). The little spark-plug-like
thermal sensor that goes into the thermostat housing.

Then I burped the engine. On a steep hill. At a very insane incline.
Then I talked to a few people. They said it might be the water pump wasn't working. I replaced (even though it wasn't broken.)

Took it to my cousins shop. She and her husband scanned it for me and determined I had some kind of head/head-gasket/possible manifold/manifold gasket related problem; along with transmission errors.

To break it down.
I have replaced:

Water Pump.
Power steering Pump.
ETI sensor
Blower Fan resistor fuse.
All 4 tires.
Breaks are new this year as well.

Here are the codes she's throwing:

C1216 EBCM Command Pressure Release 2 Long

C1224 Right Rear
Speed Sensor No Signal

C1228 Right Rear Speed Sensor Signal Erratic

C1234 Left Rear Speed Sensor Circuit Open/Short

C1235 Right Rear Speed Sensor Circuit Open/Short

C1236 Low System Supply Voltage

C1237 High System Supply Voltage

P1811 Maximum Adapt &
Long Shift

One of my rear CV boots is broken.

Anti-freeze-Lower Intake leaking

Differential needs servicing.

Power steering has a rack leak.

Rack and Pinion has leaking seals.

Valve cover Gaskets need replaced.
ABS is On, AWD disabled.

Now you guys tell me what would you do?
I have a little less then $4k to work with.

Should I do the
gaskets myself and hunt down the ABS problems?
What about the transmission?

None of these problems hit us until we had the deep freeze.
No garage.
I know nothing of transmissions.

I am just a novice backyard/shade-tree mechanic.

Should I scrap her and get something else?

You guys tell me what you would do?

Thank you in advance.

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11 answers to this question

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I think the 2002 is still the short nose. Regardless, the engine's position under the hood makes headwork a greek tragedy. You're looking at something to the order of a day and a half in a good shop for heads. I paid 11 hrs on my '97. These engines are prone to intake manifold gasket failures, and with your mileage, you're probably looking at replacing the heads. It's cheaper than having them machined yourself. All told, I paid about $2.5k for the job ... only to have a connecting rod punch right through the side of the block less than a year later.

It's still one of the best minivans out there and if you're already into it for a bunch, you have to decide if you're tossing good money after bad or not. Personally, I still kick myself for not paying for a rebuilt engine ... but knowing how much effort it is to do even the smallest jobs on it ... I couldn't convince myself (at the time) to invest more into a car that age.

ABS ... you're better off with it dead. Leave it that way.

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Not knowing much about that type vehicle. But whenever something quits putting out heat the first thing I think of is replacing the heater core.

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One thing that could be the cause of the issue and is a cheap fix. Alot of times your radiator cap seal gets old and starts leaking or sucking air causing the car to over heat and sometimes causing a steam build up due to air. 90 percent of the time it's the cap or thermostat sticking. I either drill a hole in the thermostat before installing it that is if it doesn't have a relief hole already in place which also, helps eliminate air pockets in the engine. I would install a cap and thermostat and clear all the codes before I did a rebuild. Most of the time mechanics will not troubleshoot the problem correctly and go with what is on the screen and say it is a head gasket and most of the time it is just a radiator cap. Seen this many of times!! Try that and clear the codes and see what happens. a 5 dollar repair is cheaper than a 1500 dollar repair. Just my thoughts.

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Just out of curiosity ... you didn't happen to add green coolant to the Dexcool, did you?

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Yup. I replaced the Radiator cap with a pressure release style one. Green coolant, no. Not until after the flush.

Im still debating on doing the job myself , getting a second quote or scrapping her. The shop also did a block test and there was exhaust fumes in the oil?

I dont know what would cause that?

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Any engine has a certain amount of blowby past the rings and into the crankcase. Thus the PCV (positive crankcase vent). Cheap to replace if bad.

Most vehicles operate the heat controls off vacume. You might have a leak and it's not pulling the control all the way into full heat position.

Any pin leak will let air into the heater core/ rest of the system. Check the coolant line IN to the heater core for leaks. Might not be more than a small stain on the hose.

I would disconnect both heater core hoses and flush in both directions (with a garden hose) to make sure the H core isn't plugged. You did say the gauge jumps around and Burbs before going back to normal. Might have stuff floating around in the H core. If the core was bad N leaking you would smell antifreeze and a wet spot on your floors. Another sign of a bad H core is windshield fogging up around the windshield vents from the moisture. Good luck. A LIL playin with it might save the cost of replacing the ride.

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I know I am reviving an old thread, but it is totally relevant.


So I took the heads off, (took my time) And got them to the local Machine shop. Both heads are cracked and the guy doesnt/can't do a reman job because the pins he has are junk from china?? IDK? What should I do with this thing? I mean Its ready for new or remanned heads and then gaskets and fluid and a start-up. I just want to do it right ya know..


What would be your next move?

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What I said above ... new heads. Make sure the deck is true and make absolutely sure you're using the most up-to-date intake gasket options. Pics would be appreciated. Glad to hear you're making the attempt.

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Hard to go wrong with Fel-pro

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