Automobile / GMC / 3500

GMC 3500 Truck Repair Questions and Answers

Question:  2000 GMC 3500  mileage: 109,000: My van has suddenly started blowing steady white smoke from the exhaust. At first, I thought it was a head gasket but it is using a lot of oil, yet the plugs aren't oil fouled. Compression is low on cylinders 3 and 5, but these pistons were dry. Cylinders 1 and 7, which had good compression, had oil in the combustion chamber.

Answer: We are betting on a blown gasket between cylinders 3 and 5. The white smoke is coolant turning to steam. The leak between 3 and 5 "steam cleans" the two cylinders

Question:  1999 GMC 3500  mileage: 97,000.  I have a 1999 GMC 3500 that is giving me considerable sway getting up to highway speed and on deceleration but not so much at cruising speed.  I have new 10 ply radials, balanced, proper inflation, etc.  I have 3'' springs, 6 leafs.  I have utility body, welder, torches, and tools on board, but am well under gross vehicle weight.  Leaf springs do have a little squat to them.  Would helper springs be in order or should I be looking elsewhere?  Also has rear anti-sway bar.

Answer:    Your swaying problem may be due to worn out or weak shock absorbers.  You mentioned new 10 ply radial tires – we are assuming that all four tires are new 10 ply radials.   If only two tires are radial and the other two are bias ply, this most likely is the cause of your swaying problem.

Question: 2001 GMC 3500 mileage: 104,000. The amber brakes lights have always come on and stayed on for up to two minutes after the ignition was turned on. Sporadically both lights would flicker on and go off at whim while the brake pedal would become extremely hard to depress. I was assured this was normal. However I hav0e experienced 7 complete loses of braking practically having to stand up on the brake pedal to slow done vehicle.  A local mechanic was kind enough to pick up my vehicle and take it to the shop (brakes were not functioning when he picked it up but by the time it was hooked up to the computer for diagnosis the brakes were working again, no diagnosis codes available) where he kept it for two weeks and drove it for 300 miles in attempt to have the brakes fail. No such luck. 11 days later, the brakes failed again and that is when I took it to the dealer. Brakes were working when the van was picked up. The emergency brake also failed.  When I spoke to them today they had not been able to locate the problem because the brakes were back to working again.

Answer: We had similar problems before and the only solution that worked was to replace the main ABS valve with new parts, not rebuilt ones. And thoroughly flush the brake system, bleed to adjust as needed.

Automobile / GMC / 3500

Look up more 3500 Questions in our Car Repair forum section.

Try looking up your problem in our Auto Repair topics section.

Got a 3500 Repair Question? We will answer it for free.

Replace Air Filter

Check Engine Light