Questions and Answers

Chevy Astro Van Hates Hot Days Q. Dear Vincent, I am having a big problem with my 1995 Chevy Astro Van. It has 108,000 miles on it and is maintained regularly. The van has a 4.3 liter V-6 engine. The problem only occurs during hot temperatures, 95° or above. The engine will lose power, has problems maintaining speeds above 50 mph, or sputters out until the engine turns off.

The Check Engine light does not come on. I can prevent this by letting off the gas and allowing the engine to recover. Typically hotter temperatures will dictate how often this problem will occur.

I've taken the van into the shop. They've replaced the EGR valve. Apparently there was a carbon deposit causing the valve to stick open. Two days later, the same loss of power problem occurred.

I took the service manager for a ride so he could witness the problem, and he said the fuel pump probably needed to be replaced. They replaced the pump. Another hot day and the problem returns.

Although the technicians are able to verify my complaint, they are not able to troubleshoot it, because it just doesn't act up when they are working on it.

My dilemma is this: Did I pay for parts and labor for incorrect diagnosis? And more importantly, How do I get the problem resolved? I would like to give the mechanics a chance to get it right and I do understand their difficulty in troubleshooting a problem that only occurs on HOT days. I would greatly appreciate any advice you might have.

Thank you,
Martin

A. Sounds like you're between a rock and a hard place! Only hot you say? Have they driven it with a fuel pressure gauge on it? GM had problems with EGR valves. If you went to a dealer for this he should be able to "good will" the repair since it did not fix your complaint if you talk nice to him.

This could be a case of vapor lock. This happens in extreme hot situations and a vapor bubble will form in a fuel line and cause a clot. No fuel will get by. Sometimes it can be fixed by wrapping insulation around the fuel lines closest to the heat of the engine.

Since it's a van you must be patient because they have to remove the "dog box" every time they need to work on the engine. Also, driving it with the dog box removed may make the problem not happen, see what I mean?

Have they scanned for codes? Are you using high test fuel? You shouldn't be and it could cause this problem. Let us know what you find.