Coolant System Problem

[tractive-effort]

Here's a strange one! My temperature gauge will intermitently swing from the O (on the NORMAL scale) to the A. It will sit nicely on the 'O' for about 10 mins and then rise gradually, sit at the 'A' position and then fall to 'O' again, or lower. As time goes by, the rise will get higher (though obviously I've never let it rise past the 'L' position!)

It does not lose coolant! I'm thinking either a blocked rad or faulty thermostat, but I cannot decide which?? The rad will get hot on short journeys when you stop and check, as is the top-hose. On longer journeys which involve higher RPM etc, the rad will be only partially hot (about halfway across the top half or less) and there will be a lot of gurgling and back pressure coming from the expansion tank and the hose that connects it to the thermostat housing. Also, it only really starts doing any of the above after significant mileage (say 25 miles+). And of course it has only started doing this since I got my fuel pump fixed/EGR disconnected. Strange......

PS: I also had it pressure tested yesterday by the AA, so the head gasket is OK (not that they should ever really go on a cast head like the Di, unless you really boil it... )

[stevew]

Yep, I'd check the thermostat first.

Steve

[crazyscoot]

Yep, I'd check the thermostat first.

Steve

....and a flush

[tractive-effort]

Gave it a good flush t'other day and as suspected no probs with the rad. Bottom hose off proved it today too - good flow etc!! Ran it with thermostat completely removed this afternoon and apparently it is still overheating according to the gauge at high speed/RPM. Under the bonnet says different, so has to be suspect sender-unit and gauge......nothing else it can be really I guess!?!

[AndyG]

Has it ever had a replacement water pump
The reason I ask is that there's some pumps including some newer genuine Ford pumps that come loose on their spindle intermitently with temperature changes until they become permenantly loose

The only other thing I can think of (but really can't see it myself) is an air lock

[tractive-effort]

Don't know about the water pump?? Will change the sender-unit, temp gauge and thermostat and take it from there. BTW: Anybody else had/know of anyone who has had water pump problems???

[AndyG]

You mentioned gurgling and back pressure doesn't sound like temperature sender unit to me sounds like it's telling the truth

[Gunslinger]

is there a voltage stabiliser in the system to smooth out the dashboard gauges and stop them fluctuating due to voltage changes within the system ?

[tractive-effort]

is there a voltage stabiliser in the system to smooth out the dashboard gauges and stop them fluctuating due to voltage changes within the system ?

No idea?? Though I would doubt it...

[tractive-effort]

You mentioned gurgling and back pressure doesn't sound like temperature sender unit to me sounds like it's telling the truth

Unlikely any engine with it's themostat removed would overheat on tickover though....

[FredTransit]

Does the petrol gauge go up too? That's a sure sign there is an electrical fault (that was what GS was talking about)

[ewbank]

Does the petrol gauge go up too? That's a sure sign there is an electrical fault (that was what GS was talking about)

hi just put di in mk2 tranny my temperature gauge does not work wired it to old wire from petrol engine but got extra wire a brown one is this just a earth or does it go some were else lost me it worked ok in donor van ond my old 1 worked ok can any body help cheers

[FredTransit]

Does the petrol gauge go up too? That's a sure sign there is an electrical fault (that was what GS was talking about)

hi just put di in mk2 tranny my temperature gauge does not work wired it to old wire from petrol engine but got extra wire a brown one is this just a earth or does it go some were else lost me it worked ok in donor van ond my old 1 worked ok can any body help cheers

Does the temp sender in the new engine work OK?

[MarkM]

Here's a strange one! My temperature gauge will intermitently swing from the etc etc etc

Ok partially quoted the above so the correct person answers since there are now two people taking part on this thread

Post a Picture of your actual engine showing the entire bay (close up isn't needed), if you are getting gurgles there is no way it isn't using water, gurgles are a sure sign of low water, overheating will vent off the excess, several blockages/restrictions can apply but post your engine first.

[Gunslinger]

before you go strapping that to an earth and burn a bunch of wiring out or start blowing fuses, we are going to need you to give a littel more detail on what you connected where, confirm that you had 2 wires on the original temp gauge (sounds odd to me, unless you count the light wire)
and explain where the wire you have connected goes

wiring is relatively simple if you work through things logically