Temperature fluctuations

[Kerberus]

Hi Guys,

having problems with the temperature gauge, it’s very slow to reach 90 which it does in standing traffic
But drops to 50 when on the motorway. The thermostat housing as been changed, it had been bypassed by the previous owner( temperature sender unit in the bleed screw hole ) the thermostat housing dose not have the push in sender unit, ( all in one thermostat/temperature sender ) I’ve now disconnected the old sender in the bleed screw hole ( not needed ) now I’ve fitted new thermostat housing,
The problem is still there, the car does not overheat and runs well, I’ve driven the car with my fault code reader connected and the live data shows a steady temperature reading from the thermostat housing but the gauge goes from 90 to 50 on the motorway and eventually returns to 90 at standstill



dean

 

[Kerberus]

Hi Guys

have finally sorted the problem with the temperature gauge, with the help of a good wiring diagram I checked the grounding to the loom which is connected to the fan relay, when the car reached it’s operating temperature the relay would go open circuit causing the gauge to drop back to 50 degrees and slowly rise back to around 90 degrees. I had previously checked the ECU for faults relating to the heating circuit but found none. Since changing the relay the gauge is now operating as per normal

 

[neilgsxr69]

Thanks for sharing that’s definitely going to help owners in the future

 

[Gkerry]

i have the problem but mine is taking ages to reach to 90. engine light comes on. went to shop tonight engine still warm so engine light went off. in the morning this will happen again. any help.

 

[Kerberus]

i have the problem but mine is taking ages to reach to 90. engine light comes on. went to shop tonight engine still warm so engine light went off. in the morning this will happen again. any help.

Hi
You say the engine light comes on, is this the high temperature warning light or the engine fault light ( yellow engine symbol ) if this is the yellow engine light it means there’s an issue with one or more of the systems and a fault code as been stored within the ECU, you will need a good fault code reader to check the ECU. I’ve found most heating problems relate to the thermostat housing and sensor, some but not all have a separate push in temperature sender unit and some don’t it’s part of thermostat housing. There are a few different thermostat housing on the RCZ. I would check the ECU for any faults and go from there.

 

[Gkerry]

It’s the engine light. Cones says engine fault repair. Needed. I’ve only just got it back from garage. And still doing it after £550 the machine showing nothing it’s driving me nuts. Now. It’s clearly still doing it. Didn’t even drop it back soon as finished work boom came back on

 

[Gkerry]

Yes same thing happend when came to work.

 

[Gkerry]

any help please.

 

[Kerberus]

any help please.

After paying £550 pound and you still have the same fault is very frustrating, was the garage made aware of the issues you was experiencing with the car and did they promised to find and correct the issues. I can’t help but wonder why they charged you £550. If they had you believe they could fix the car and then subsequently charged you for finding nothing. In my mind that’s a clear breach of contract between you and them.

 

[Kerberus]

After paying £550 pound and you still have the same fault is very frustrating, was the garage made aware of the issues you was experiencing with the car and did they promised to find and correct the issues. I can’t help but wonder why they charged you £550. If they had you believe they could fix the car and then subsequently charged you for finding nothing. In my mind that’s a clear breach of contract between you and them.

 

[Gkerry]

It went in for an oil leak. And several other codes came up which fixed all then got it back I started it up from work engine light came back on but I noticed still the temperature gauge was taking ten mins to get to 90.

 

[Gkerry]

He said is had an undocumented code which means nothing at all

 

[Gkerry]

Said it’s just like a light coming on an off as it as no code with it.

 

[Kerberus]

Intermittent faults are a real problem to sort especially if nothing is being recorded on the ECU. On most top end fault code readers there is a live data stream function which will relay live information from the cars ECU while it’s being driven this can in most situations help to pin point problems you are experiencing. The ECU is programmed with a set of values which it uses to monitor things like air and fuel ratio, turbo boost etc, any inputs to the ECU outside of these values the car will generate a fault code and switch the Null light on.

 

[Gkerry]

what do you suggest

 

[Kerberus]

what do you suggest

I would keep using the vehicle until at some point this intermittent fault becomes permanent, hopefully it will store a fault code which would enable you to pin point the exact cause of the problem. Providing the car is not over heating and maintaining a good oil pressure you shouldn’t run into any major problems. It’s not wrong being cautious and keeping an eye on things, the RCZ is not without its problems as most of todays vehicles also have inerrant faults

 

[Gkerry]

No not over heating. Engine light not come on today at all. Weird.

 

[Kerberus]

A few years back there was a problem with fuel from one of the refinery’s, it caused all sorts of problems, mainly emissions based problems which caused major failures of the lambda sensors ( before and after the Catalytic converter in the exhaust pipe ) my 53 plate RCZ will throw up a fault code if I run the vehicle on super unleaded, Peugeot recommend 95 Rom as stated on the fuel cap, indecently it was nearly all super markets which had the problem with the fuel contamination. I only ever use shell or Esso fuel and won’t bother with super market crap

 

[Gkerry]

no i never use supermarket fuel. heard all sorts. no lights at moment so will just see vey odd how it came on yesterday but nothing today.

 

[Pedro]

Apparently using the wrong octane in the BMW Prince engines can & will affect engine temperatures