Engine cutting out with thermostat fitted & EML on/off - Help!!

My 1996 1000cc petrol Hijet van has a weird problem. The engine light(eml) on the dash only goes off when the engine is cold, If I take the thermostat out, it only comes on intermitantly.

Now with the new thermostat fitted (as when I got the van it didnt have one!), once the engine reaches normal temperature on tick over, the engine dies and wont start till its cooled down - can anyone help as my head is starting to hurts now

Also, the tick over seems a little eratic, but that might just be me as I've only had the van for a week so still learning its parculiarities.

Hope someone out there can help.

RED

does it take forever to move the temp needle? There is no bottom stop on the gauge only the needle itself so could be removed and refitted at a lower temp and no stat is to make an engine run colder by not isolating the block to bring temp up to normal in a shorter time the eml comes on when engine overheats no matter what the gauge shows. look in the manuel section I think the engine codes are on there now if you short out the terminals on the diagnostic plug as the manuel show is will give you a code which should answer the problem to erase the old codes you have to disconnect the negative lead on the battery for a few seconds then refit that way you could run it up till the light comes on and only see the current prob but I would check the code first and compare.

rich the mechanic wrote:does it take forever to move the temp needle? There is no bottom stop on the gauge only the needle itself so could be removed and refitted at a lower temp and no stat is to make an engine run colder by not isolating the block to bring temp up to normal in a shorter time the eml comes on when engine overheats no matter what the gauge shows. look in the manuel section I think the engine codes are on there now if you short out the terminals on the diagnostic plug as the manuel show is will give you a code which should answer the problem to erase the old codes you have to disconnect the negative lead on the battery for a few seconds then refit that way you could run it up till the light comes on and only see the current prob but I would check the code first and compare.

Hi Rich, thanks for the reply, i've now flushed through the coolant & refilled (new rad fitted by prev owner) the temp gauge doesnt move off cold, it only moves atiny bit when the ignition is switched on. The engine runs & the heater works, however, the fan wont come on. I've switched the wires from the bottom of the rad to the fan & the fan stays on, I'm not sure which plug--bottom of rad/fan motor is which as I dont have a wiring diag. But theres 12v at one plug which is connected to the bottom of the rad.(thats the one I connected to the fan to make sure that the fan works) So basically, the engine starts, the eml goes out, the heater works BUT the temp gauge and the fan doesnt, what do you rekon old chap?

Totally agree with rich, check what codes its giving you otherwise your basically keeping your eyes closed. It'll tell you which sensor is giving bizarre, erratic or zero reading, or define what is see's the problem as.

You may have a temp sensor thats gone duff, or the wiring or just the connector.

This may mean that the ECU thinks the engine isn't hot, thus cannot correct the fueling correct for the idle. Also maybe why your electric fan never kicks in.

You may find when you fix it you will get better MPG's and performance.

Agreed check history first then go from there.

Thanks for the reply guys, I need a code reader then, where does one obtain one of those? are there specific readers for specific vans or are they a generic reader.

It's built in PM me and I will send you a copy of the codes from the manuel so long as you have a 3 cylinder 993cc but under the dash in the passenger footwell you need to look for the 3 pin plug there is a pic on the door of mine which shows which terminals to connect to do the timing it is the same ones for the ecu code all it does is flash the eml on the dash and you can match it to the book. it is a large file I sent it to someone before and I could only send the section with the codes as anymore was to big.

You do not need a code reader. Just a paper clip and the list of code numbers/definitions.

I've cleared the ecu by dissconecting the neg on the battery, re-connected the battery and connected the test link at the ecu.

Fault code---4 flashes then 2 repeated.
Manual states-- coolant temperature sensor.
Is that the sensor on the engine just under the handbreak? or the one on the radiator.

The wiring diag. shows the one on the engine having 2 thermistors, one of which feeds the temp guage, which isnt working in my case. So I'm leaning towards that one, but I might as well change both--(belts and braces theory)

So just to confirm, is the cooling sensor for the engine fitted to the manifold under the cross member which the handbreak is bolted to?
thanks

RED wrote:I've cleared the ecu by dissconecting the neg on the battery, re-connected the battery and connected the test link at the ecu.

Fault code---4 flashes then 2 repeated.
Manual states-- coolant temperature sensor.
Is that the sensor on the engine just under the handbreak? if not, where please.

The wiring diag. shows the one on the engine having 2 thermistors, one of which feeds the temp guage, which isnt working in my case. So I'm leaning towards that one, but I might as well change both--(belts and braces theory)

So just to confirm, is the cooling sensor for the engine fitted to the manifold under the cross member which the handbreak is bolted to?
thanks

To add a note: I've removed the sensor from the bottom of the rad & put a meter across it, heated it up and the sensor seems OK, so it must be the engine coolant sensor, which I'm having dificulty identifying, not sure where to look. Cheers.

Not 100% sure, but usually they are in the cylinder head at one of the ends where the water feed/return, or in one of the coolant pipes. Sorry not that helpful!

Well done for testing the sensor! Impressed by your efforts Red.