can sparkplugs make your engine run hotter?
Thread Starter
Racer
Joined: Jun 2006
Posts: 256
Likes: 0
From: Fresno Ca.
While you said you had checked, I just want to be sure you looked carefully under the front of the vehicle into the "plenum" where air from the road is drawn up and through the A/C condenser and radiator. These cars are "bottom breathers" and love to suck paper/plastic bags, leaves, and other trash off the road and into the A/C condenser, which then blocks cooling air to the radiator. A paper bag from MickeyD's will substantailly raise your coolant temperatures ..... 
Instructor
Joined: Nov 2007
Posts: 129
Likes: 1
From: Houston, Texas
Ok, here’s another thought. Was the AC on when you observed the higher coolant temperatures? Turning on the AC triggers the fans to turn on, so perhaps the AC was off during your recent temperature check. On cool days when I don’t use my AC, coolant temperature will climb to some 220F when idling, or while creeping in stop and go traffic. However, with the AC on temperatures will remain around 190 – 200F, even in traffic. I know you mentioned that your fans were working, but were they on because of the AC, or did the higher temp trigger them on? Check your temperature with the AC on and while in traffic and see if it isn’t cooler.
Thread Starter
Racer
Joined: Jun 2006
Posts: 256
Likes: 0
From: Fresno Ca.
Ok, here’s another thought. Was the AC on when you observed the higher coolant temperatures? Turning on the AC triggers the fans to turn on, so perhaps the AC was off during your recent temperature check. On cool days when I don’t use my AC, coolant temperature will climb to some 220F when idling, or while creeping in stop and go traffic. However, with the AC on temperatures will remain around 190 – 200F, even in traffic. I know you mentioned that your fans were working, but were they on because of the AC, or did the higher temp trigger them on? Check your temperature with the AC on and while in traffic and see if it isn’t cooler.
Racer
Joined: Feb 2007
Posts: 431
Likes: 5
From: Chico CA
Long long ago, in a galaxy far far away, I was a young, underpaid newby geek who couldn't afford to drive a cool car to work. So I had a Honda Civic. Flame away.
Anyway, my shop did a tune-up and didn't get #4 plug wire fully seated. It was arcing to the plug, giving a low-power spark and a poor burn on that cylinder. The poor little 1.3 liter engine ran really hot, particularly on hot Central Valley days (I lived near Stockton at the time), and when climbing the Altamont Pass.
The shop couldn't figure it out. The car ran fine, just 30-40* hotter than a week ago. They charged me $75 to install a S-W temp gauge on the premise that the in-dash gauge was wrong (on a two year old car). Still hot. That's where I got the temperatures, in fact - the factory gauge was one of those C----|--H jobs.
Finally I was just fooling with the car and found that #4 wire just pulled off at a touch. Didn't need a tug or anything. No snap, no click, just slipped off the insulator. I pushed it back on, got that nice terminal click, and the car cooled right back down. Convinced me that I could do the maintenance on the DD Honda as well as on the BB Mustang. And I haven't paid for a tune-up again.
Check your plug wires. They should click on. If not, the cooling systems on these cars are as sensitive as the old econoboxes were - they have to heat up fast to meet smog requirements. If a wire is damaged or not seated good, you could be getting low spark, low power on one cylinder, and more heat from the others to make up for it.
Just a guess, but one I've observed before in real life...
Anyway, my shop did a tune-up and didn't get #4 plug wire fully seated. It was arcing to the plug, giving a low-power spark and a poor burn on that cylinder. The poor little 1.3 liter engine ran really hot, particularly on hot Central Valley days (I lived near Stockton at the time), and when climbing the Altamont Pass.
The shop couldn't figure it out. The car ran fine, just 30-40* hotter than a week ago. They charged me $75 to install a S-W temp gauge on the premise that the in-dash gauge was wrong (on a two year old car). Still hot. That's where I got the temperatures, in fact - the factory gauge was one of those C----|--H jobs.
Finally I was just fooling with the car and found that #4 wire just pulled off at a touch. Didn't need a tug or anything. No snap, no click, just slipped off the insulator. I pushed it back on, got that nice terminal click, and the car cooled right back down. Convinced me that I could do the maintenance on the DD Honda as well as on the BB Mustang. And I haven't paid for a tune-up again.
Check your plug wires. They should click on. If not, the cooling systems on these cars are as sensitive as the old econoboxes were - they have to heat up fast to meet smog requirements. If a wire is damaged or not seated good, you could be getting low spark, low power on one cylinder, and more heat from the others to make up for it.
Just a guess, but one I've observed before in real life...
