Engine Running Cool - Not Thermostat Problem..? Help.
Discussion
Hello..
My engine seems to be running cold and thus rich. I changed the thermostat for a new one and it still seems to have the same problem, what should be my next step?
I didnt 'test' the old 'stat (will do tomorrow) or the new one so cant be 100% that they're not at fault. I went for a 15 minute drive and temp guage made it about a 1/3 of the way around, I stopped on my drive with the engine running and after a few mins with a bit of throttle now and then the guage did rise to just below half and the fan kicked in.. I thought all was well but then back on the road the guage went back to moving between 1/3 and 1/5.
I've not checked the heater runs hot yet either..
While I know bits and bobs I'm far from a mechanic.. Any ideas please?
Car is an Integra Type R, DC2.
Cheers, Greg.
My engine seems to be running cold and thus rich. I changed the thermostat for a new one and it still seems to have the same problem, what should be my next step?
I didnt 'test' the old 'stat (will do tomorrow) or the new one so cant be 100% that they're not at fault. I went for a 15 minute drive and temp guage made it about a 1/3 of the way around, I stopped on my drive with the engine running and after a few mins with a bit of throttle now and then the guage did rise to just below half and the fan kicked in.. I thought all was well but then back on the road the guage went back to moving between 1/3 and 1/5.
I've not checked the heater runs hot yet either..
While I know bits and bobs I'm far from a mechanic.. Any ideas please?
Car is an Integra Type R, DC2.
Cheers, Greg.
Gompo said:
That's the logical next step I was thinking but how do I go about testing it? Would it be a case of getting a replacement and swapping it over or is there some way of checking it?
You could try using something like this to see what the temperature of the cooling system is : http://www.amazon.co.uk/Silverline-633726-Infrared... and also to check for localised hot spots (just in case).Thanks marshalla. I think I'm just going to get a new sensor (after checking they're only about £10) and see what happens. It looks as though it's possible to check the resistance of the sensor with a multimeter which I may have a go at but at the moment I cant see how it could be anything else but the sensor.
Your help is appreciated, I know it can be a pain in the arse.
Once I know it's warmed up I tend to drive it quite enthusiastically, I've obviously been a bit apprehensive about doing this when the temperature gauge isnt doing as it should (yes I know it's the oil temp I should be worried about, I usually give it atleast another 5 mins after the water's up there).. While trying to see what it's doing this weekend I've taken it a little more steady but still gone through most of the rev-range enough, sat at traffic lights etc.
Your help is appreciated, I know it can be a pain in the arse.
davepoth said:
That leads me to believe it's working properly. How are you driving it on the road?
I had the same thought initially too, but as in the first post one I drove off it reverted back to being problematic. The temp gauge is definitely not how it used to be, it used to take about 10 mins to get to 1 notch below middle and stay there 95% of the time. Looking on the Integra forum practically everyone says similar and if it's sitting much below this there's a problem. It's not an every day car so fortunately I've never experience what it does in a traffic jam for example, I think yesterday was the first time I've had the fan kick in. Once I know it's warmed up I tend to drive it quite enthusiastically, I've obviously been a bit apprehensive about doing this when the temperature gauge isnt doing as it should (yes I know it's the oil temp I should be worried about, I usually give it atleast another 5 mins after the water's up there).. While trying to see what it's doing this weekend I've taken it a little more steady but still gone through most of the rev-range enough, sat at traffic lights etc.
Done a bit more messing - drove for 20mins or so, gauge still the same. Let car idle for a bit same as before, decided to unplug what I believe is the coolant sensor and the idle speed rose a fair bit. Would it rise when unplugged if the sensor was faulty anyway?
davepoth said:
One other thought - I don't know this, but does your car have a thermostat controlled oil cooler?
95% sure there is no oil cooler.Gompo said:
Done a bit more messing - drove for 20mins or so, gauge still the same. Let car idle for a bit same as before, decided to unplug what I believe is the coolant sensor and the idle speed rose a fair bit. Would it rise when unplugged if the sensor was faulty anyway?
if the stat is working and is the corect one!! it must be the gauge sender or gauge reading low !!! it simple if the stat is closed water stays in the block if its open the water circulates through the rad and cool water goes back into engine and the stat starts to close untill the heat load increses then it opens again this is if you are driving and there is air flow though the rad, If the car is running and not moving the rad will get hotter untill the stat is fully open and the water returning to the engine is the about the same temp there will be a sensor which opperates the fan when the coolant reaches a pre set level maybe around 95c so it should seem to get hotter stationary as there is no air flow untill the fan comes on davepoth said:
One other thought - I don't know this, but does your car have a thermostat controlled oil cooler?
95% sure there is no oil cooler.so then the fan setting is controling the engine temp not the water thermostat...
Thanks for the reply Powerstroke. I understand how the thermostat works, but the original 'stat seems to be functional and so should the new one - but the problem/issue is still there. Even if it was just the gauge that was faulty, I don't think I'm imagining the unburnt fuel smell..
..just don't know where to go from here?!
..just don't know where to go from here?!
You said in your first post that the car is running cold and hence rich, how do you know the car is running rich, has you mpg changed since the cooling was ok?
Have you spoken to others with the same car, how do their temperature gauges compare to yours?
Does your temp gauge have an inbuilt voltage regulator, if so is that the problem as it will show a low temperature reading if it is faulty, giving you a low temp indication?
Is the temperature sender ok, is the wiring ok?
After seeing that your original thermostat was working ok, did you have a thermometer checking the temperature when the temperature increased? As I seem to recall you saying you heated the water first then put the thermostat in it and it opened, that tells you that it works but it doesn't tell you that it works correctly. You need to fill a saucepan with cool water drop the 'stat in then with a good thermometer sensing the water temp put it on the cooker to start to heat the water. The 'stat should open at, or around, the prescribed temp (what ever that is for your engine) and close on cool down. Then you will know of it is working correctly.
Just a few pointers for you to check, hope you get to the bottom of it......
Have you spoken to others with the same car, how do their temperature gauges compare to yours?
Does your temp gauge have an inbuilt voltage regulator, if so is that the problem as it will show a low temperature reading if it is faulty, giving you a low temp indication?
Is the temperature sender ok, is the wiring ok?
After seeing that your original thermostat was working ok, did you have a thermometer checking the temperature when the temperature increased? As I seem to recall you saying you heated the water first then put the thermostat in it and it opened, that tells you that it works but it doesn't tell you that it works correctly. You need to fill a saucepan with cool water drop the 'stat in then with a good thermometer sensing the water temp put it on the cooker to start to heat the water. The 'stat should open at, or around, the prescribed temp (what ever that is for your engine) and close on cool down. Then you will know of it is working correctly.
Just a few pointers for you to check, hope you get to the bottom of it......
Gompo said:
Thanks for the reply Powerstroke. I understand how the thermostat works, but the original 'stat seems to be functional and so should the new one - but the problem/issue is still there. Even if it was just the gauge that was faulty, I don't think I'm imagining the unburnt fuel smell..
..just don't know where to go from here?!
Check for fuel leak perhaps!!!! The engine will be running at or higher than the opening temp of the stat!!! that is simple phyisics.. it cannot do anyhing else unless the ambiant temp is very low sub 0c or it hasnt run long enough Cane the tits off it and stop worrying.... your gauge is reading a little low ......just don't know where to go from here?!
phumy said:
You said in your first post that the car is running cold and hence rich, how do you know the car is running rich, has you mpg changed since the cooling was ok?
Have you spoken to others with the same car, how do their temperature gauges compare to yours?
Does your temp gauge have an inbuilt voltage regulator, if so is that the problem as it will show a low temperature reading if it is faulty, giving you a low temp indication?
Is the temperature sender ok, is the wiring ok?
After seeing that your original thermostat was working ok, did you have a thermometer checking the temperature when the temperature increased? As I seem to recall you saying you heated the water first then put the thermostat in it and it opened, that tells you that it works but it doesn't tell you that it works correctly. You need to fill a saucepan with cool water drop the 'stat in then with a good thermometer sensing the water temp put it on the cooker to start to heat the water. The 'stat should open at, or around, the prescribed temp (what ever that is for your engine) and close on cool down. Then you will know of it is working correctly.
Just a few pointers for you to check, hope you get to the bottom of it......
Phumy, thanks for your reply. I can answer a few of your questions. Unfortunately I probably wont get to have another proper look at my car until the weekend.Have you spoken to others with the same car, how do their temperature gauges compare to yours?
Does your temp gauge have an inbuilt voltage regulator, if so is that the problem as it will show a low temperature reading if it is faulty, giving you a low temp indication?
Is the temperature sender ok, is the wiring ok?
After seeing that your original thermostat was working ok, did you have a thermometer checking the temperature when the temperature increased? As I seem to recall you saying you heated the water first then put the thermostat in it and it opened, that tells you that it works but it doesn't tell you that it works correctly. You need to fill a saucepan with cool water drop the 'stat in then with a good thermometer sensing the water temp put it on the cooker to start to heat the water. The 'stat should open at, or around, the prescribed temp (what ever that is for your engine) and close on cool down. Then you will know of it is working correctly.
Just a few pointers for you to check, hope you get to the bottom of it......
Running rich?
OK, I'm not 100% on this and should have probably said over-fueling which may be considered different. Before I noticed the gauge not reaching it's normal temperature I noticed a petrol smell when I pulled up with the windows open. At first I thought it could have been a minor fuel leak as I'd had one on a previous car to similar effect. I've not really noticed a change in MPG, but firstly I've probably only done 100miles since I first noticed the fault so not long to to determine and secondly I very rarely drive at a steady/average enough pace to know what rate the fuel needle goes down anyway. No MPG readout or anything.
Other owners temp gauges
The same as mine used to be before all this, about 10-15mins and the needle should be just below half on the gauge and stay there. This is from info on the Integra Forum.
Temp sender ok?
Cant be sure on this now after I've messed/pulled/pushed around with bits and bobs this past weekend, but see no reason why it wasnt before and during the initial problem.
Check thermostat open/close temps
No I've not measured these, I simply put the 'stat in the microwave with water. Not scientific I know, so of course it could be staying open too long - but that doesnt answer why the new one seems to be doing exactly the same. The new one was supposedly a genuine Honda part as opposed to a pattern one.
I think I'm going to have to wait until the weekend and try to do some more digging and testing. Maybe start again with the old and new thermostats etc.
Powerstroke
Fuel leak was the first thing I checked for as it was the initial smell that triggered all this! Not saying it hasnt got one but I did have a good look and sniff around the car while it was running and couldnt find anything..
I'm a little embarrassed this thread has gone on so long without conclusion, I'd hoped there was a simple answer (maybe there still is and I'm worrying too much) but while I know the car isnt worth much I try to look after it as much as possible in terms of mechanics. Roll on the weekend, or not!
Your ECU may use water temp as part of the map.
If it thinks the water is cold, it will bring the choke in as the engine is cold -> petrol smell.
If your sensor is underreading it can effect the map, depending on how clever the ECU is etc.. but given unplugging it resulted in the idle changing I'd say it's almost certainly informing the ECU's decision & I'd get a new temp sensor in there.
It seems so unlikely that the REAL water temp isn't up to 'proper' temp given you've switched thermostat and see the same result, that is MUST be the coolant temp sensor, and I'd wager that it's also the source of your adding extra fuel to the mix.
How much is a new sensor?
If it thinks the water is cold, it will bring the choke in as the engine is cold -> petrol smell.
If your sensor is underreading it can effect the map, depending on how clever the ECU is etc.. but given unplugging it resulted in the idle changing I'd say it's almost certainly informing the ECU's decision & I'd get a new temp sensor in there.
It seems so unlikely that the REAL water temp isn't up to 'proper' temp given you've switched thermostat and see the same result, that is MUST be the coolant temp sensor, and I'd wager that it's also the source of your adding extra fuel to the mix.
How much is a new sensor?
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