My check engine light and service asr light started coming on intermittently. The CE would go out after a few moments but the ASR light would stay on until the car was turned off and back on. She was throwing about 5 different codes, not all of which I was able to find. (I don't have the service manual.) The ones I was able to find pointed to a throttle position sensor error. I took her in to the dealer and they diagnosed a failed TPS, but they said it failed due to oil getting into the sensor. I had them diagnose the oil issue and they said the bottom end seemed to be solid, although they couldn't say for sure without actually looking inside the engine, and that the issue seemed to be in the heads. They recommended a head rebuild, for an estimate of around $3500.

How hard is it to pull and replace the heads? I'm far from a mechanic but I'm not afraid to get dirty and I've done everything from simply alternator and water pump type replacement to putting a junkyard engine in my '90 Ranger. My primary concerns with doing the pull and replacement myself are specialty systems like the ASR. How much stuff has to be pulled out of the way to get to the heads? Are there any special calibration or reassembly issues that would cause a shade tree piddler any problems?

Second, are there any reasonably priced performance mods that I should do in the process of having the heads done? Does having these heads ported make sense from a bang-for-your-buck perspective? Any other suggestions?

Thanks in advance!

 

Pulling the heads can get a bit involved. Before starting this project get a good service manual and see if you are up to the task. Your biggest gains from a set of ported heads will be combined with a matching camshaft. So, that makes the project even more invasive. Just to get your current heads rebuilt (no Porting) should be around $300-$500.

 

agreed. I think it would bbe 3500 bucks down the drain. I think they have misdiagnosed you problem. How would oil from the heads, against gravity, get up to the TPS?. Bet they don't know for sure what the problem is, and figured for 3500 we'll eventually find it taking the heads and everything else off

 

I was wondering if that made sense myself. That's why I put the question mark in the title of the post. According to the dealer, the oil is getting sucked into the vacuum system. I don't know enough about the LT1's vacuum system, TPS and the rest of those systems to know if it makes sense or not. If the heads are not the issue, what might cause this? And if I can't trust the dealer to accurately diagnose it, then who? The reputed difficulty of diagnosing TPS and ASR issues is the reason I went to the dealer in the first place. Any advice?

 

As a bit of extra info, I do notice a little bit of smoke when the car is first started. It's not much, barely visible, and it goes away after the car warms up. It's light colored smoke, which would likely indicate coolant, not oil. That could be a head issue but if so, it would seem to be unrelated to the oil issue.

I have 117k miles on the car, and I've been told that it's not at all unusual for there to be a little smoke when you start the car with that many miles on the engine.

 

This is just a simple start. But, try replacing the PCV valve.

 

Sounds like valve seals, a ~$30 fix if you do it yourself.