Hi Guys.

I have an issue with my 2008 H3 3.7 L with about 114000 miles. This has been going on for a while and I can't seem to track down whats causing the problem. After numerous forum/internet searches and trips to the dealer no one has come up with a solution. The problem occurs after I drive the truck and get it up to operating temperature then shut if off and let it sit of at least an hour (it has done it after sitting for 4 hours). When I go to restart it, it will sputter and bog or some times stall and takes an extra few cranks to start if it stalls. If the truck is cold it will start fine and if its hot and I shut it down and restart it, it will fire up with know problem. I have no codes or engine lights. The dealer has replaced the cam positioning solenoid, they replaced a broken rear exhaust manifold stud I found and even installed a new exhaust manifold and O2 sensor (the latter I did have a light for). I replaced the plugs with the oem ones and put dielectric grease on the coils. I once had a code for small evap leak but I cleared it and it never returned.

Thanks for taking the time to read all this. If anyone have any ideas please share what you think it would be. If I'm missing any info let me know.

Thanks - Joe.

 

Replace the ECT sensor. GL



http://www.napaonline.com/Catalog/Ca...732_0306491251

Btw, make sure that dexcool is full and clean!

 

What makes you think it's the temp sensor? My gauge always shows between 1/4 and 1/2 read out.

 

Because it is a common problem with your symptoms, and a cheap/easy fix.
You could go and buy some equipment to diagnose it yourself, or pay someone to diagnose it, however that cost alot more than the $12.00 sensor that you can install yourself.

If your vehicle starts to use a lot more gasoline than usual, or black smoke is starting to come from the exhaust pipe, these are indicators that the coolant temperature sensor in your vehicle could be defective, and needs to be replaced. If you start having trouble starting your vehicle or runs rough after it has reached its normal operating temperature, this is usually a very good sign that you need to have the coolant temperature sensor checked.

Btw, your gauge shows lower than normal operating temperature for the H3!

Also, the ECT sensor controls alot more than the gauge, and it couldn't hurt to replace it, even if it does not correct your issue.

Summary of engine control system

 

Cool, thanks for the info. Ill give it a shot.

 

Just checked part info. The 1 I listed above is for the alpha..

The I5 is a different part number acdelco 213-4233 (gm # 12601050)

ACDelco OE Service Engine Coolant Temperature Sensor Cool Temp Sensor | eBay

Napa ECH TS5748

http://www.napaonline.com/Catalog/Re...Dp%3d3%26N%3d0



#313

 

Well I replaced the temp sensor, the thermostat and flushed and replaced the coolant yesterday. Immediately I noticed the temp gauge was reading a little over half while I has letting the truck warn up and it stayed there on the way home also. My hot air is now hot again which is a good thing during cold upstate NY winters. I did just start the truck after letting it sit for about two hours after my ride in to the office at it still sputtered on start up. Now I'm thinking I have a leaking injector.

 

Well here's a little update. I pulled the intake manifold and replaced the injectors. I also replaced all the coils, the intake manifold gasket and the valve cover gasket (I had a little leak and figured while I had the intake manifold off why not). Most of the intake manifold bolts were loose and what a pain in the a$$ it is to pull that thing off. I found that my alternator was missing one of the top two bolts and installed a new one. My truck still has the rough start on semi warn start ups! The search continues...

 

I have this exact same problem. Been going on for quite awhile now . I have replaced much of the same parts. Did you ever resolve the issue?

 

Im having the same problem and have replaced the same parts y'all have and nobody can seem to figure it out