2003 Chevrolet Impala


George Pierce

August, 10, 2010 AT 3:26 PM

Engine Performance problem
2003 Chevy Impala 6 cyl Front Wheel Drive Automatic 171000 miles

My 03 Impala began losing power under load, I had code scan done by an ASE shop. They said the codes indicated a misfire and overheating. They said that the intake manifold gasket was leaking coolant. I changed the intake manifold gasket and the T-Stat. I check the EGR valve and found that it was apparently stuclk because I checked it by checking the plunger valve with a small screw driver. I felt a small " pop". I took the valve apart and cleaned it with WD40, then wiped the valve dry and used air to dry the excess oil. After installing the new manifold gasket, the engine did not accelerate any better. IT just seemed to fall flat when trying to accelerate above 18-20mph. I was driving it out of town on a 20 mile trip. After about 4 miles the check engine light came on again. A friend had a scan tool, when we checked for codes it came up with a p0300 code. This was after I had changed the plugs, the IACV, it was stuck and I messed it up taking it a part, so I replaced it. I've changed the plug wires and cleaned the plugs I changed the fuel filter and checked the air filter. We checked for a vacuum leak by using carb cleaner around the air plenum, etc. What should I check and in what order? I am retired with high medical cost and therefore I have to try to make the repairs myself. Thanks, George


2 Answers



August, 10, 2010 AT 3:55 PM

Two things to do have fuel pressure checked and clean MAF if 3.4 L in air intake plenum if 3.8L see diagram

Let me know
Thanks for donate



August, 10, 2010 AT 4:02 PM

When the intake gasket was fixed, did they do this?
Reference Number(s): 03-06-04-056, Date of Issue: September 29, 2003 Related Ref Number(s): 03-06-04-056 ARTICLE BEGINNING SERVICE INFORMATION A new gasket has been released for use in the above vehicles. The new gasket will seal better than the previous gasket. When changing this gasket, be sure to check the bottom of the throttle body for any flashing. Any flashing that protrudes more than 0.50 mm (0.020") should be filed by hand. Use caution that the sealing surface is not damaged. Flashing in the areas indicated between the arrows, ( Fig. 1 ), is the most critical as it can effect the sealing of the upper to lower intakes. Be sure that all surfaces are clean of any foreign material before installing new gasket. Fig. 1: Throttle Body PARTS INFORMATION
BUICK: 2000-2003 LeSabre, Park Avenue, Regal with 3.8L V6 Engine (VIN K - RPO L36) CHEVROLET: 2000-2003 Impala, Monte Carlo with 3.8L V6 Engine (VIN K - RPO L36) PONTIAC: 2000-2003 Bonneville, Grand Prix with 3.8L V6 Engine (VIN K - RPO L36) SECTION: 06 - Engine/Propulsion System

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