Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 1999 Chevrolet S10 owners, lightly cleaned up (personal details are redacted by NHTSA).
TSB #030601024a -- rattle noise in engine. (NHTSA id #10004301, March 01 2004) #6 rod cap stretched, causing bearing to fail. Also other bearings began to fail. Possibly due to coolant leak from intake manifold gasket or just very defective part - mechanic unsure this of a vehicle that is properly (sometimes overly) maintained. Have all service records to prove it. Even mechanics commented on upkeep of vehicle. Service facility refuses to make repairs - trying to force complete engine replacement even though crank journals can be polished, new bearings can be put in and rod can be replaced. Basically they and GM are looking for a big payday - they are sadly mistaken. I have had nothing but problems with this vehicle, with each repair becoming more and more expensive. I now have to get rid of the truck and have financial hardship due to the costly repairs. …
Engine rattles due to balance shaft between 1800 and 2000 rpms, replace with timing tensioner kit. GM has a fix for this with a TSB number and all, but will only fix vehicles with original 3 year 36,000 mile warranty. They literally invented a part to install that should have been installed from the factory due to overwhelming complaints. I was under my GM 5 year 75,000 mile warranty and they even had my engine apart rebuilding under warranty and would not install the new timing chaintensioner to eliminate rattle. The rattle indicates meteal on metal contact, and eventual wear. I had a warranty, and they would not fix it. Very frustrating. We ended up buying a Toyota tacoma for my wife, thus ending any future purchases with GM. I still have truck, and May pursue this in court. It basicaly affects every 4.3l eqipped GM vehicle, so they only pick and choose who to fix. …
It's a 99 s-10 v6 / 4.3liter rarely driven, 62,000 miles on the vehicle. No real event leading to the problem. Right now it is leaking radiator fluid from the front of the engine block. I cannot see where the leak is directly as it picks and chooses days to leak and not leak. It hasn't overheated or anything yet. It still has the original radiator fluid in it from when I bought it. I keep telling my mechanic we need to flush or just change the fluid. For over 6 months he keeps saying its fine. It drips onto the skid plate under the engine and drips from there. Never a huge puddle just enough to make a 2 foot diameter wet spot. Nothing has been done yet. Mechanic says to put kars radiator stop leak in it. I have a long road trip coming up in 2 weeks and afraid to take it out of town.
For the second time my 1999 Chevy s-10 pickup has been taken to the transmission shop because I have lost second gear and reverse. This is a costly repair, the first time it cost me $1,600.00 to replace a $44.00 part because the whole transmission had to be overhauled. The transmission in the Chevy is made with inferior parts and should be recalled to have all the gears replaced. I have also had to replace both front wheel hubs and a motor. The s1-s of this era need to be investigated and the consumer should be protected!!
Tl contact owns a 1999 Chevrolet s-10. While the vehicle was parked, the contact noticed thick rust dripping from the engine of the vehicle. He took the vehicle to a service mechanic and was informed that the intake manifolds were rusted out, as well as the water pump, radiator, and all of the hoses. The vehicle has not been serviced for the failures and has not been diagnosed by the dealer. The current mileage was 104,636 and failure mileage was 63,000.
While driving 30-35 MPH, a fire started in the engine compartment. Dealer and manufacturer were notified. The engine had already stopped and vehicle was coasting when the fire became evident. The brakes were non-funtional, consumer stopped the vehicle by means of emergency brake. Truck was consumed and totally engulfed in about five minutes. Total loss.
Consumer has had multiple problems with vehicle. A/C wires burned out the clutch fan. Dealer claimed wires weren't where they were suppose to be. Cooling fan went through the hood. Dealer said it was a manufacturer's defect. A month ago when the A/C wires burned out, they detected it. Dealer didn't offer a loner vehicle.
The transmission did not shift into gear. It felt as if the gear was in neutral, consumer was informed that water and transmission fluid came out of the transmission breather which caused the fluid to turn pink, and the transmission needed to be replaced. Also the engine stalled on occasions.
Vehicle been experiencing ongoing / intermittent problem with engine stalling while driving at any speed. Dealer notified, and some repairs were made. But dealer informed consumer that there is no guarantee that the problem will not reoccur. Seeking help in this matter from NHTSA.
My oil lines have failed twice. Based on an s-10 mailing list I belong to, failure of these is a common occurrence. In fact, after 1 week of buying this truck new, I noticed the oil lines were leaking.
Engine complaints in other S10 years
Frequently asked questions
How common are engine problems on the 1999 Chevrolet S10?
NHTSA has 22 complaints about the engine & cooling of the 1999 Chevrolet S10, 10% of the model year's 231 complaints. The component named most often is engine › gasoline (11 mentions).
Is there a recall for 1999 Chevrolet S10 engine problems?
No. NHTSA lists no engine & cooling recall for the 1999 Chevrolet S10. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 1999 Chevrolet S10 engine problems start?
Half of the complaints with a recorded mileage happened before about 63,000 miles, and 14% before 25,000 miles.
Is it dangerous?
Owners linked 0 crashes, 1 fire and 0 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.