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A place to talk about your non-LH current or former vehicles.

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User avatar
 #333045  by adu1982
Ok so my parents own a 02 Buick Rendezvous..... about 3 years ago it started having some weird overheating issues.....roll to today and some 3000 my parents spent on different nechanics.... it still does the same rhings just worse.

So i know these cars are prone to bad bcm, head gasket and electrixal problems...i have been reading....but the buick forum is small, inactive and the solutions very limited.

I think (i saw the newer lim gasket) that they did do the head gasket, my dad had the old aater pump and thermostat so all that is rather new.

Now for the does not loose colant, it has good ac and heat but , especially on hot days the temp gauge passes half mark all the way up to 3/4, then with or without ac comes back down then goes up after a while ..etc
Also when started dasboard lights are ok, no check/service engine soon, then as soon as you put it in reverse/drive the lights dim to where during the day you cant see (CENSORED), trac and abs come up on their own, ac doesnt work on max setting, sometimes works......

More weird i pulled the bcm, tried a junkyard bcm...same thing......i ran it without bcm......the lights on the dashboard seem fine.

Tonight i pulled the carpet off as because of ac there is always water (my dad said for a while) so i will check fix that.

Also another thing that gows crazy when this goes on, the outside temp sensor will show right temps most of the times but sometimes way way lower temps...llike freezing or even display ICE when its 90 degrees. Last night i drove the car and it seemed to act almost normal.

Could the bcm i tried from the yard have the exact same issue you think its all wires?

What if i ran the car for lets say 50-100 miles with no see how it acts that ok?

What else can show all these weird things on and off......

User avatar
 #333170  by adu1982
A 3.4
Gaskets should have been changed (my dad had it a shop in miami where he lives..about 1800 for from what i remember head gasket, lim, top cover that cracked.....I can see the lim is newer).

Water pump & thermostat have been changed .... i found them in the trunk in a box.
User avatar
 #333246  by FIREM
2002 Buick Truck Rendezvous V6-3.4L VIN E

Vehicle / Engine, Cooling and Exhaust / Cooling System / Description and Operation

-Description and Operation

Cooling System Description and Operation

Cooling Fan Control
The engine cooling fan system consists of two electrical cooling fans and three fan relays. The relays are arranged in a series/parallel configuration that allows the Powertrain Control Module (PCM) to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage from the underhood accessory wiring junction block. The ground path is provided at G100.
During low speed operation, the PCM supplies the ground path for the low speed fan relay through the low speed cooling far relay control circuit. This energizes the cooling fan 1 relay coil, closes the relay contacts, and supplies battery positive voltage from the cool fan 1 fuse through the cooling fan motor supply voltage circuit to the left cooling fan. The ground path for the left cooling fan is through the cooling fan 2 relay and the right cooling fan. The result is a series circuit with both fans running at low speed.
During high speed operation the PCM supplies the ground path for the cooling fan 1 relay through the low speed cooling fan relay control circuit. After a 3-second delay, the PCM supplies a ground path for the cooling fan 3 relay and the cooling fan 2 relay through the high speed cooling fan relay control circuit. This energizes the cooling fan 2 relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time the cooling fan 2 relay coil is energized closing the relay contacts and provides battery positive voltage from the cool fan 2 fuse on the cooling fan motor supply voltage circuit to the right cooling fan. During high speed fan operation, both engine cooling fans have there own ground path. The result is a parallel circuit with both fans running at high speed.
The PCM commands Low Speed Fans on under the following conditions:

-Engine coolant temperature exceeds approximately 106°C (223°F).
-A/C refrigerant pressure exceeds 1310 kPa (190 psi).
-After the vehicle is shut off if the engine coolant temperature at key-off is greater than 140°C (284°F) and system voltage is more than 12 volts . The fans will stay on for approximately 3 minutes. The PCM commands High Speed Fans on under the following conditions:
-Engine coolant temperature reaches 110°C (230°F).
-A/C refrigerant pressure exceeds 1655 kPa (240 psi).
-When certain DTCs set.

Engine Coolant Indicator(s)
Hot Coolant Temp
The IPC illuminates the hot coolant temp indicator in the message center when the PCM determines that the coolant temperature is greater than 128°C (262°F). The IPC receives a class 2 message from the PCM requesting illumination.
The IPC sends a class 2 message to the radio in order to activate an audible warning
User avatar
 #333316  by velobard
We have a 2003 Aztek, pretty much the same as your Buick. About the first thing we did was take it in for a flush and fill and the shop warnd us to NOT use the recommended coolant, but the standard long life green stuff and said the other stuff was hard on components like the gaskets. All I can say is that the universal coolant has worked fine for us. Don't know if it has anything to do with your problems or not, but thought I'd throw it out there. I used to mock and laugh at people who drove Azteks, but we have come to really like ours.
User avatar
 #333349  by adu1982
Yeah i will do that thanks.....i got a new radiator, rad cap...approved one and coolant engine temp sensor and i will putting regular coolant since the other stuff in there are rather new (pump,tstat,gaskets) i hope new rad will bring it to where it just stays at half and needle doesnt jump all over.

Is your aztec pretty steady.....needle temp wise......?
Does it go over half mark towards the 3/4 mark????
User avatar
 #333419  by velobard
The Aztek is pretty good with engine temps unless something is wrong. We have an excellent radiator shop that can also take care of most of our other repair needs. As much as we like it, the engine isn't as durable as a Chrysler. The main headache we've had is that rocker arm bolts have pulled out a few times. We like the car enough that when it happened again recently we decided to drop a new crate motor into it. It should be finished next week. Most people would think we're crazy to put that into an Aztek, but we figure we'll wind up with a better car than we could get for that money elsewhere. It can haul a stack of 4x8 plywood, has a tent and custom air mattress for the back for camping, can hold more than many SUVs (we found that out one day when we had to transfer a load from it into a 4-Runner), and if I'm willing to take it easy, close to 60 mph, I have repeatedly been able to get 32-33 mpg on the highway. I don't know how that's even possible, but I have done it several times.
User avatar
 #333447  by adu1982
Yeah he put some money in it already, i just spent another 1000 ( of which 500 is just a nifty bluetooth touch dvd with back up camera, sensors, etc...) . So in short he will keep it. I have about 3 weeks left to get it in better shape. I just got the new radiator from rock auto so i will be replacing that. Hopefully it will bring it down just enoguh to stay at half without that 3rd fan shady solution.
User avatar
 #333448  by adu1982
Another weird issue i have....

At night or daytime ( with sensor covered) the service engine light goes off. The lights still dim but no...service check engine except for daytime. Code scanner doesnt show anything when service light is on.
User avatar
 #369011  by adu1982
Another yearly vacation for my folks back home so the POS 02 Buick Rendezvous 3.4 was here for repairs.
Squared away some issues (front hubs, alternator, driver CV shaft, inner rack boot). About ready to take it back at the end of this week and there she goes last night.
Cruisin at 90 (in a rush to get to work on time) at the end of my 20-25 minute commute she started jerking and once I pulled in our work's parking lot she died twice on me and restarted right away. Needless to say the Buick forum is like a haunted no help.
Googling gets some suggestions : tps sensor, crank shaft sensors (there are 2), camshaft, fuel pressure regulator.
She has no codes (got erased when I changed the alternator before vacation). History codes did show 2 for o2 sensors (even though it has oem cat and sensors from about 2 years ago...30k).
Rather new (few months) rebuilt oem maf sensor. Got 182k on it.

She did it once or twice on the way home this morning but small jolts did not die.
Any ideas?

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User avatar
 #369015  by hrmwrm
plug in under the floor behind the driver seat is notorious for causing problems. stalling, idle problems. no start. i've fixed a few now.
montana, rendezvous, aztec, all the same.
pull it apart, clean/dry connections, and see if it helps. sometimes they might need direct wiring if badly corroded.
mostly just moisture causes some glitchy running.
last one i did was plagued by a high idle. put the scanner on, and i could control it down, but it wouldn't on it's own. somebody had spilt beer on the floor in the backseat.
User avatar
 #369017  by adu1982
I Know about that. I will rechecked but last time I wrapped it real good in electrical tape. Check engine came on this morning. Can't wait to get home later today and see what actron will read.

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User avatar
 #369025  by adu1982
3 codes....P0137 (history, confirmed, pending).....
The 02 where both replaced but at 40$ I'll replace the post one again. Added a 16oz can of seafoam in the gas tank too last night. No jolts or stalls last night or this morning.....will see.

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User avatar
 #369156  by adu1982
After burning my fingers with hot coolant...yes ...I did that....was mad that it was getting late and we still had to drive to Miami do I opened the return coolant pipe while hot with gloves on. Got it to Miami chugging as hell so I applied a hunch from here and changed the crank sensor and that did the trick apparently. Left it there and took the Fit back. Ordered the parts for the Fit so rebuild should start next week.
Got some already: hood, bumper etc....

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