Buick Rendezvous Idles Very Low and Engine Light On

Problem with my 2003 Buick Rendezvous service engine soon. Question: I just bought a 2003 Buick Rendezvous 2 weeks ago. It has 78800 miles on it and started acting funny today. At idle and at very low speeds (when we're first taking off, backing up or slowing down) the car starts to sputter/jump and feels like it wants to cut off. At normal speeds, the car runs perfectly fine. Any ideas?

I will be more than happy to make a donation when I get paid on Friday! Please help if you can. I just spent $8200 buying this car from an individual and I am so upset! Thank you so much for you time.

buick rendezvous

ANSWER:

By what you are describing, it sounds like your engine has a misfire. This is a condition were a cylinder is not firing properly. Your condition is a misfire 'under load'.

Most misfires under load are caused by a problem in the ignition system. IE- spark plug, plug wire, ignition coil. What you need to do is have the computer scanned for codes. Anytime the SES (check engine) light is on, or was on, the computer stores a code(s) related to the problem. This would give an indication as the what system is having a problem.

Far from popular belief, a computer scan does not tell a tech WHAT the problem is, just what system is having a problem, and the general area to begin diagnosis. Most of the large national parts store chains can do a scan for free.

If the problem gets worse, or the SES light starts to flash, this indicates that the problem is bad enough to cause possible catalytic converter damage, so it should be looked at ASAP, since catalytic replacement can be very expensive.


Question:
This car temperature gauge registers very hot about 2 minutes after it is started. When this happens the manifold and the radiator continue to be barely warm and the heater only puts out cold air. When the overheating light comes on the car will only travel at about 25 mph. The thermostat has been replaced. What now?

Answer:
This sounds like a common condition on the V6 in your buick. The fact that it gets a hot temperature reading on the gauge right away, yet the hoses and manifold and heater are cold tells me you are getting air in the cooling system. Air cannot transfer heat from coolant. This is most likely caused by a blown head gasket. The head gasket can be blown and leak externally or internally. When internally, combustion gases and pressure are forced into the cooling system causing air pockets.

Air pockets prevent coolant from flowing causing the engine to overheat. The rear head gasket is usually the problem. You can tell this by removing the rear spark plugs and looking for signs of burning coolant which would be orange deposits. Or you can look from under the passenger side of the car up to the rear cylinder head and see coolant leaking down the engine.


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