Welcome to the SR20 Community Forum - The Dash.
SR20 forum logo

Thread: Overheated last night - doesn't want start today

+ Reply To Thread
Posts: 71-79 of 79
2010-09-24 14:27:09
Yes that's normal.
2010-09-24 14:34:17
Thanks again BenFenner.

2010-09-24 16:48:27
5 pages of how to fix coolant issues and next to zero discussion of WHY his car won't start. Unreal.

Half or worse of the "logic" being offered here is pure crap w/re to leading to resolution of your problem. It's super easy to have someone state a problem with a bunch of leading info that takes you down the wrong path, I understand that. After 5 pages however, someone here should have said forget the overheating issue for now, follow the basic "car does not start" troubleshooting steps! WTH, 210/212 deg F is normal in hot weather, 217 vs. 214 deg is noise!

[INDENT]1) Unless compression is completely off the bottom of the scale, the basic NA motor will still run even with crappy compression. It just runs down on power and usually due to ring issues it will drink oil. From what I see here, the car was running hot but otherwise not awful, wasn't belching blue or white smoke, etc. So yeah, compression test a good idea, but not before you figure out why the motor isn't even running, it's not a "first step" unless the motor is FI, highly tuned, etc.

1) Oil temps in excess of 250 deg F can occur with much lower coolant temps (yes, like 220-230) and wreak havoc on the motor. I didn't see an oil pressure gauge or oil temp gauge. Yes 210 or 212 deg is normal for coolant, but no, the levels of coolant temps are no guarantee that your oil temps didn't spike a hell of a lot higher. I cannot count even using both hands the number of dead SR20's I have seen due to oil overheating, lack of oil pressure, lack of oil, etc. I can count the number of blown head gaskets, etc, on one hand, which is more relevant to 'coolant too hot'. But none of those symptoms are present. And, if the car has been sitting overnight, and is stone cold, a bad coolant temp sensor isn't likely to keep it from starting. Oil-related damage in normal use is a gradual process for normal engines, not sudden death,

2) Oil around plugs is irrelevant to the OP's problems. Anyone who has owned Nissan I-4's for more than a few years knows the o-ring seals are good for ~5 years or so, they just tend to leak with age. Has zero to do with damaged head issues, the VC clamps those down against the collar around the plug. Non-issue, fix it when you can, soak the oil out and watch the dipstick level. Buy a new VC gasket at the same time. Also realize you may see some evidence of misfiring on a plug that was left soaking in oil for way too long, but that's a rough running issue, not a "won't run" issue.

3) Car will run from a cold start a)with one, b)without one or c) with a stuck thermostat. It may get hot quickly, but most of the time our tstats fail OPEN, not closed. Car tends to take a long time to warm up, that's about it for problems unless you are talking Winter use. I've had three failed OEM thermostats, all three failed open. If they fail closed that happens usually when they are new and defective, not many thousands of miles later. And even it it's missing or the thing is shut, it won't stop the motor from trying to fire up. If closed, motor will just start to get very warm after normal op temps (e.g. 175-180 deg F). BUT - motors that don't start, and don't run, don't have overheating issues, short of parking the car in Death Valley in summer or dropping it into a volcano.

What you should have heard page one is follow the basic troubleshooting steps for a car that does not start, do not get sidetracked on an issue that yes, you need to deal with, but is pretty irrelevant if the motor does not run. These steps are so well documented I'm not going to waste space and time repeating them. Until you methodically check the usual culprits, you're wasting your time. You would have done better to pick up a consumer manual for the car than the advice you've gotten here w/re to getting the car running.
2010-09-24 17:04:49
^ ........
2010-09-27 14:33:43
I changed the coolant temperature sensor over the weekend. The car started with no issues, the Nissan Data Scanner is reading correctly and the T-stat is working as it should. I will go into more details later.

2010-09-27 15:09:14
Excellent. Sounds like a happy ending. Sorry I was so doom and gloom at the beginning. I'm glad you're back up and running properly.
2010-09-30 03:19:33
After thinking about what happened - I don't think the car actually overheated.

The coolant temperature sensor (CTS) malfunctioned and sent the incorrect info to the ECU causing the fans to come on at 210 and add the wrong fuel mixture. That night I drove home the Nissan Date Scanner (NDS) showed 210 most of the time which was what the malfunctioning CTS was telling it. Real temp was most likely 185-190 which was about what the temperature gauge cluster was showing. I also had the heat blowing at full blast. When I finally got home there was no coolant leaking or boiling. The next day when I tried to start the car the incorrect fuel mixture from the day before had fouled up spark plugs making it difficult to start and the bad CTS also was sending the wrong info to the ecu.

If I didn't have the NDS I would of had a hard time figuring out what was wrong if anything. I think the fuel mileage would of been poor and the car would of been difficult to start. When I checked the ecu a week later for codes, nothing came up for a CTS . Has anyone else ever experienced anything as bizarre with a bad CTS?

2010-10-01 17:37:45
Drove the car to work today with no issues and the coolant temperature on the NDS read 177 on the highway. It was reading 190 on the highway before I flushed coolant system and added new coolant & distilled water.

I also passed the emission test today!

2010-10-01 18:45:39

Yes other people have experienced the same things with a dead CTS.
+ Reply To Thread
  • [Type to search users.]
  • Quick Reply
    Thread Information
    There are currently ? users browsing this thread. (? members & ? guests)

    Back to top