Thread: Pulling my hair out

By ecu you mean engine ecu if there was oil in the connections to the ecu then you need to clean the oil out of the main engine wiring harness (or put a new harness in) as well also the ecu has to be sync and the injector codes have to be put into the ecu that was borrowed.

Originally Posted by CO011

.....

When I start her up from cold she idles fine at approx 800 rpm, then surges up to 1200 approx for a few seconds then back down, repeat a couple of times until the temperature gauge falls to below cold and the red light comes on.

.... Currently running a loaned ECU from a mechanic, was ok when the car was hot. Cooled down, restarted. Same issue.

Once the temp gauge drops down there’s no more grumbling from the car and she runs fine.


..... I get warm air at my feet when the car is warmed up, however the heater is intermittent. The car isn’t over heating from what I gather. Oil is black, not milky.

.....

I think you may need to explain in a bit more detail.
Some of the explanation appears to be contradictory, or confusing.

To start with you said "start from cold" ... explained an issue, but then went on to say "until the temperature gauge falls to below cold" and what do you mean by the red light? Which red light(on the temp gauge?)

Red light on gauge comes on when too hot. Is your red light coming on when the gauge reads cold?

With the intermittent heater .. do you mean air coming through, or actual temp?
That is, is the fan blowing, then stopping then blowing again? .. or is the air blowing all the time, but the temperature drops from hot/warm to cold?

Originally Posted by PETER S

By ecu you mean engine ecu if there was oil in the connections to the ecu then you need to clean the oil out of the main engine wiring harness (or put a new harness in) as well also the ecu has to be sync and the injector codes have to be put into the ecu that was borrowed.

The ECU was changed over by a mechanic with codes etc updated.

Will take a look at the wiring harness, cheers

Originally Posted by AK83

I think you may need to explain in a bit more detail.
Some of the explanation appears to be contradictory, or confusing.

To start with you said "start from cold" ... explained an issue, but then went on to say "until the temperature gauge falls to below cold" and what do you mean by the red light? Which red light(on the temp gauge?)

Red light on gauge comes on when too hot. Is your red light coming on when the gauge reads cold?

With the intermittent heater .. do you mean air coming through, or actual temp?
That is, is the fan blowing, then stopping then blowing again? .. or is the air blowing all the time, but the temperature drops from hot/warm to cold?

RE start from cold I mean starting the vehicle up for the first time. When the temperature gauge on the dash begins to rise it starts from blue. When the gauge fails, the dial falls below the blue, similar to when the vehicle is off. The red light is the small light above the temperature gauge on the dash.

The red light comes on approx 2 minutes after starting the vehicle, so the car is cold. Prior to the light coming on a dial falling, it surges as decribed originally.

Air comes through the heater but it’s cold when I switch it on. Air comes through when the aircon/heater is not switched on as normal.

Cheers

The red light is an overheating warning, it could be putting the engine into protection mode. Check the temperature sender and water pump.

Has the coolant system been bled correctly?

There is a thread on how to do it somewhere on here.

I think it was by Dave Blknight,or others may chime in on how its done.

If its not done properly the heater wont work correctly,and causes other issues.

Just a thought.

OK then .. sounds like a diabolical electrical issue.

So when the car is stone cold from start, and everything 'appears' to be normal, the engine surges? this part is still unclear.
Then after some time, as it warms, but is still effectively cold .. I'd estimate maybe 40-50°C in about 2 mins here in Melb .. the temp gauge needle drops, and the red light lights up?

Just prior to this 'event' the engine starts to surge?

Going off your opening post tho, it sounds like from stone cold engine runs fine.
Then as it gradually warms up, there is a period where the engine surges and then there is this 'anomaly' with the temp gauge warning light comes on, and the gauge drops(ie. effectively isn't working).

Warm air through the heater from start .. I find it takes up to about 5 mins to get some in cold weather here in Melb.
I use nanocom pretty much all the time, I (used too) have a run to work regular as clockwork. It's a 5 min run to a set of lights where I wait there for a cycle, which takes about 2 mins to get me going onto a main road .. and then a half hour non stop drive to work.
From start to those lights .. is about 5 mins. I don't have any issues, but coolant will reach about 50-ish(give or take 5) degrees by the time I'm at the lights. If I this same run on a regular day where heater isn't needed, it'll get to 60ish degrees to the same point.

So in two mins you won't really have a lot of heat from the coolant through the heater.
I've always found that once into the 60's is when I feel any heat through the vents at max heater temp.

for now .. and not knowing where in Melb you are, I'd say best path forward is to locate a local member with a nanocom and get some data off there.
And for a TD5 D2, my go to recommendation is to get your own nanocom unit to have at hand.

If you're not too far away, I wouldn't have any problem coming over, connect up the nanocom whilst she's cold and see what messages it spits out.
Otherwise if you're a bit too far , or closer to another members area .. start a new post in the forum asking for assistance from any locals with a nanocom.

Are you north/south/east/west?

sounds most likely that the coolant sensor is giving strange readings .. ie stuffed! ... for it to set the warning light so early, and then basically stop working.

going of the manual, sounds like most likely cause is coolant sensor failure.

In the event of an ECT sensor signal failure any of the following symptoms may be observed:

Difficult cold start.

Difficult hot start.

Driveability concerns.

Instrument pack temperature warning illuminated.

Temperature gauge reads excessively hot.

Temperature gauge reads excessively cold.

it then may be using the fuel temp once it realises that the ECT sensor is whack .. and then runs kind of normal.

Make sure that the connector is all the way in the sensor connector. Maybe give it a spray WD or INOX or something .. could be a dirty connection.

Most likely plan to replace it.