Weird problem and far from home

[racy7]

car is esprit s4 (1995). On holiday and nearing end of trip. Engine check light has come on and noticed that water temp has dropped from 70 to 35 !!!

stopped the car went for a coffee and on return started car and of course no engine check light. nothing obvious to see, no leaks  and everthing seems to work as normal. Car drives fine.

What do the experts on here think, serious or will it get me home (500 miles)

[Bibs]

Might be worth checking if there are any codes coming up?

 

[MPx]

Hopefully you also checked the coolant level?  Drop in temp suggests lack of coolant where the sendor is.  Poss air in the system or just not enough runny stuff?  

Not sure if its the same on the S4 but on the G-cars the system needs to be bled to eliminate air - various methods:   Sparky even told me about a bleed tap that I didn't know existed - doh!  Method I use, when the car is cool if not cold, I get the car on a very steep slope so that the back of the car is way higher than the front.  Take the cap off the metal header tank and run the engine on idle til the thermostat opens.  Watch the bubbles come out of the canister and once that stops and its just liquid to the brim, switch off, cap back on and fill the plastic expansion tank to the marked level.   

[Dave Eds]

Mike and coolant........... 😄 

[MPx]

Long time ago Spud...and we kept most of it off the track!

[drdoom]

Sensor should be considered suspect, and do physically check for coolant temperatures at specific points.

[Chillidoggy]

The CEL doesn’t illuminate unless there’s a reason, but that doesn’t mean whatever it’s flagging up is a terminal condition. I’ve had the same issue with the coolant gauge being a bit wafty before, with no other symptoms, or CEL showing, and no fault codes being indicated. And the system was, and is, free of air. The important thing is the engine coolant sensor is working.

It’s got oil pressure, it’s got coolant, there’s no obvious leaks or performance issues. If it were mine, I’d drive it home and sort it when I got back.

 

[Escape]

The S4 has 2 temperature senders, one for the ECU and one for the dash. So unlikely to be a sender, as you saw the temperature drop on the gauge and the ECU obviously also saw something wrong to give a CEL.

As above, use a paperclip to check the error code, verify coolant level (don't forget the expansion tank in the left rear corner!) and I'd also check for any lose wires/poor connection/bad earths that could cause faulty readings for both the gauge and ECU.

Good luck!

Filip

[madmax]

How do you tell which contact is which on the ALDL plug hidden away under the rear offside wing when making the paperclip jumper? My S4 is still dead!

My service notes appear to be missing the required section.

Thanks

[Bibs]

Click the link I posted above 👍

[Escape]

As the link to the article in the topic mentioned above is no longer working, I might as well paste the description here. ALDL pin A = black wire, pin B = white/black wire.

ALDL_field scan.pdf

[Erikl]

Very curious, once you get it sorted report back please.