Two Issues

[taxman82]

I have a 2003 trailblazer with about 175,000 miles on it. This is a third vehicle for my family and we use it quite frequently during the winter months and for short in town runs. I have recently run into three issues.

The first was solved by my local dealer (thank god my brother in law is a service writer). I was smelling gas for a few weeks but didn't see anything under the trailblazer. Took it to a local shop and they replaced the fuel pressure regulator. Long story short that was not the issue turns out the sending unit rusted through. Apparently GM knows about this and expended warranties which I am still within for time but not mileage. At any rate my connections at the dealer saved me over $1,000 all together because they couldn't get the fuel lines off it was so corroded. Now its time to fight with GM over what I would consider a known unsafe condition.

Onto the two issues remaining. This morning while driving to work I started hearing a sound like one of those can mufflers. Thought at first the civic in front of me may have been the culprit but when I was cruising alone on a smooth road it was still there. Seems to come on over 30 MPH. I just had new tires put (a little brother in law help with those too) on and it did seem to just come on suddenly. I am not sure if it goes away at higher speeds as I was pulling into town when I heard it.

Second outstanding issue is a cold start knock. You can hear the knock slightly when it is cold and idling, more when driving before the temp gauge moves off of the bottom and not at all once it has warmed to 210. That takes until I am just about to hit the highway about 5 - 10 minutes of city driving. Once I reach 210 it is perfectly quite.

Any ideas on the outstanding issues is appreciated.

[Tech II]

The first was solved by my local dealer (thank god my brother in law is a service writer). I was smelling gas for a few weeks but didn't see anything under the trailblazer. Took it to a local shop and they replaced the fuel pressure regulator. Long story short that was not the issue turns out the sending unit rusted through. Apparently GM knows about this and expended warranties which I am still within for time but not mileage. At any rate my connections at the dealer saved me over $1,000 all together because they couldn't get the fuel lines off it was so corroded. Now its time to fight with GM over what I would consider a known unsafe condition.

What caused the fuel smell? Which sending unit are you talking about? Rusted connections on a 10 year old car? Good luck with that one.....



This morning while driving to work I started hearing a sound like one of those can mufflers. Thought at first the civic in front of me may have been the culprit but when I was cruising alone on a smooth road it was still there. Seems to come on over 30 MPH.

Possible wheel bearing?



Second outstanding issue is a cold start knock. You can hear the knock slightly when it is cold and idling, more when driving before the temp gauge moves off of the bottom and not at all once it has warmed to 210. That takes until I am just about to hit the highway about 5 - 10 minutes of city driving. Once I reach 210 it is perfectly quite.

Piston slap?

[taxman82]

The fuel smell was coming from the fuel sending unit above the gas tank. It was completely rotted out and corroded. GM knows about the issue and extended the warranty to 10 years and 100,000 miles. My argument is that mileage shouldn't matter because it is a safety issue.

I was thinking the bearings as well. The job doesn't look to difficult I just need to find some time to take care of it.

Piston Slap.. I didn't think about that. I know that my grandfathers truck has that pretty bad until it warms up but I didn't know these has that issues as well. I always take it easy or let it warm up before I leave. Hopefully I can keep her going for a few more years.

[Schurkey]

Originally Posted by taxman82

Piston Slap.. I didn't think about that. I know that my grandfathers truck has that pretty bad until it warms up but I didn't know these has that issues as well. I always take it easy or let it warm up before I leave. Hopefully I can keep her going for a few more years.

www.pistonslap.com

I've got a pair of early-90's Luminas with piston slap so bad you'd think it was a rod knock. Knock sensor is pulling timing, fuel economy is down about 3--4 mpg on the highway.

Been like that for ~ten years or more. No particular problem with oil consumption. Just annoying as hell, and GM has abandoned all responsibility for a provable design flaw.