Coolant Temp sensor or me killing my Q?

[FDR Dippin]

Can a bad coolant temp sensor cause LOTS of fuel filled white smoke? Reality is i've prayed and tomorrow is in God's hands! I trust i didn't just sacrifice my Q!.

The cost of doing an injector and plug job, just wasn't sitting well with me, I was quoted $2700 and just couldn't rationalize it, as much as i like and need my car, that was simply unreasonable to me!

So I purchased a set of plugs from joe and a set of advertised NEW! OEM purple tops from EBAY and payed a shop to put them in. When i picked up the car, i immediately realized the vibration or shakes i was feeling was still there. I also smelled fuel which i guess i expected considering the job. Well, i pulled off and PUFF and cloud of trailing smoke consumed the car behind me. I drove about 1/4 mi to see if it would blow out and had to turn around. WHAT did i do? Rather what did they do? or WHAT did i buy? What's causing this?The shop pulled the plugs to see if any were wet and ALL on the side they pulled were wet. They think they installed all o rings OK and think it unlikely the damaged ALL.So.... they check MAF...OK. They scanned ECU and said they had coolant temp sensor hard code!No check engine light and no noticeable high idle. Could this be the cause of EXTREMELY rich fuel mix? Before this job, i never saw smoke from my car... by the time most of you read this it'll be morning and FEDEX would have delivered the sensor and it'll be put in. But tonight, i just wonder could this possibly have coincedentally gone bad or did the shop f-up the injectors and/or plugs?

[goody90q45]

....... i just wonder could this possibly have coincedentally gone bad or did the shop f-up the injectors and/or plugs?

It's the shop's fault. One of the lower o-rings in the leaky bank is not seated properly. Hopefully it's on the passenger side where you have a 2 out of 4 chance of reseating the injector o-ring without removing the plenum. (#2 and #8). The odds aren't so good if it's the driver side leaking (#1 only).

When I had a leaker early in ownership the entire bank was flooded (like you) and raw fuel was flowing out the cat and tailpipe. Don't drive- You're close to hydrolock and closer to a potential fire.

[Q451990]

Ditto on Mike's assessment. You have a pinched lower o-ring. I would have them pull that rail again and pressurize it while it's unbolted from the runners to determine which one is leaking. Shame on them for giving it back to you that way! Independents and shade tree mechanics with little or no Q/early Z experience can be a dangerous experiment - not that dealerships don't screw this up sometimes too.

If your Q survives this, be sure to have the oil changed - it is surely contaminated with fuel by now. As a side note, one coolant temp. sensor is part of the injector harness, and the other one is part of the knock sensor harness. One is for the dash gauge and the other is for the ECU... I can't remember which one is part of which harness...

Your code is probably a result of something they unplugged cut or otherwise damaged while they were in there. There is no way that a disconnected or bad temp. sensor would cause this type of issue... so be sure they don't start the car again and try to diagnose it in that direction more. If the car isn't at the shop now, don't try to drive it or start it... have it flat bedded back. Or better yet, get them to agree to have a qualified shop take over and have them pay for it! How far is "Mac town, GA" from Atlanta and T3's experts?

Heath

[maxnix]

Yes to all the above!

Incompetent mechanics and bad owners are the top sources of demise for most Q45.

T-3 is your answer.

[Q45tech]

Never seen a failed temp sensor on Q, sure dirty corroded ones and bad connections but failed totally no. Nothing some clean up cannot fix.

[FDR Dippin]

Well as an update I got my car back yesteday. The shop replaced the Temp sensor and voila. No smoke, no shakes, great acceleration. I guess all's well that ends well. After reading these initial posts, i was very nervous that the sensor wasn't the real culprit here but bad workmanship.

This trip to the repair shop I replaced all plugs and injectors and decarboned the plenum and egr. I guess the more i drive the car over the next few days, it'll reveal its new true nature, but for now 1-120mph, start to ...hard stop, all seems well.

As a note, I'm not sure if the temp sensor was broken or not, they did say that it appeared corroded and should be replaced, so i did. Cleaning it was a suggestion and i assumed no different.