Camaro and Firebird: Engine Performance Diagnostic Guide

This article applies to the Chevy Camaro and Pontiac Firebird (1998-2002).

The LS1 is an awesome engine that is nearly bulletproof. However, like all engines ever made, there can be some small issues that cause performance loss. If you notice a sluggish motor or unusual noises under the hood, the fix can most likely be found in this article. The first step to take with any diagnostic repair is to see if your engine has any OBD-II codes stored in the ECU, which might reveal the problem or provide clues. Read on to find out more information about some common problems and their fixes for the LS1.

Step 1 – Squeal from belt tensioner

Worn out belt tensioners tend to squeal over time and need to be replaced.

If you open your hood and hear a squealing sound coming from your belt or belt tensioner, an easy method to diagnose the problem is to get some WD-40 and spray it the the surface of the belt to see if the noise lessens. Be aware that if you use too much, you will have WD-40 splatter all over the engine bay. Also, use the straw attachment to accurately aim the spray. If the squeal remains, then spray some WD-40 on the center of the belt tensioner to see if the noise lessens. If it does, then simply replace your belt tensioner and your problem will be gone!

Step 2 – Sluggish top end power

This is most likely caused by fuel starvation by a faulty injector, pump, or filter.

The fuel system needs to be in tip-top shape to provide max performance out of your LS1. If your fuel filter is slightly clogged, you will impede flow and your engine will be starved for fuel at the higher end of your revband. Be careful, as this can cause detonation and lead to engine failure. Therefore, it is best to replace your fuel filter, even though it may not be the source of the problem, because it is cheap to replace and ensures your fuel system is working right. If that doesn't solve your problem, then proceed to test your injectors by getting them flow tested. If they check out all right, then the problem is most likely your fuel pump and can be upgraded while you are replacing the stock pump.

(Related Article: How to Replace Fuel Filter - LS1Tech.com)

Step 3 – Faulty knock sensor

A faulty knock sensor will cause your LS1 to run very conservatively.

A knock sensor is used to sense detonation in your combustion chamber. If it goes bad, you will get a check engine light and notice that your LS1 feels sluggish. Without the safety of the knock sensor, the LS1 defaults to a limp mode tune to make it safely to a repair shop or dealership. If you are savvy with doing work on your LS1 yourself, this job is not hard to tackle on your own and can be done in under a couple hours.

Step 4 – Bad tune or aftermarket modifications without tune

If your car has an aftermarket tune on it, it may not be set correctly!

An ECU tune is a very sensitive component of your LS1's performance. Having a good tune allows you to run maximum timing without detonation and allows for great drive-ability, even with more aggressive cams and other mods. However, if your detonating or your air fuel ratio is not right, then your LS1 will not run at its potential. If you don't know the history behind your car's tune, then it is a good idea to have a reputable local tuner read the ECU to see where you are at! Also, if you have done mods without a tune, then your car will not run right because the computer needs to be able to compensate for the increased fuel demand and other parameters.

Step 5 – Irregular oil pressure

Oil pressure fluctuation is a serious problem that needs to be looked at.

If your oil pump is on its way out, it may start to act up and not provide sufficient oil pressure to your engine. This can cause sluggish performance and eventually engine failure. If you notice these symptoms, replace your oil pump immediately. It is not worth risking your engine! While you have access to the oil pump, you can also choose to upgrade your cam, replace the timing chain, etc.

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