Overheating after 2.1 conversion

[1_eyed_jim]

Got my 2.1 fitted the other day and it got to the bleeding part and I'm stuck. When I removed the 1.9 I found out the thermostat had been taken apart and it was basically permanently open! So on the 2.1 I've fitted a brand new thermostat from Brickwerks.

The problem I've got is that the needle on the gauge is on the far right with the LED flashing but radiator is still cool and the thermostat is still closed?? The cab heater is belting heat out though. I've pointed a infrared thermometer at stuff and the pipes around the engine are only up to 80 c. Could this be a faulty coolant sender?

When I put the bodged thermostat in the radiator is warm and the fan cuts in when the needle is about 3/4. Is there such thing as a 2.1 dash pcb?

Thanks Rob

[123-jn]

sounds like you may have a short in your gauge sender wiring or your sender has gone open circuit. Use a multimeter and check that the sender has a reasonable resistance when cold. And check the wiring to see if it has a short to earth. Have you refitted the same sender as you had in before? The stat starts to open at 85 degrees c so it wont be open at 80. It doesn't completely open until over 100 degrees!!! sounds like it could be a temp sender problem. The Other possibility is the level sender in the header tank, if the water does not reach the prongs of this , this will also send a signal to the gauge to flash at you. My radiator is old and not so efficient so I have ordered a stat that will start to open a bit sooner for mine .

[1_eyed_jim]

sounds like you may have a short in your gauge sender wiring or your sender has gone open circuit. Use a multimeter and check that the sender has a reasonable resistance when cold. And check the wiring to see if it has a short to earth. Have you refitted the same sender as you had in before? The stat starts to open at 85 degrees c so it wont be open at 80. It doesn't completely open until over 100 degrees!!! sounds like it could be a temp sender problem. The Other possibility is the level sender in the header tank, if the water does not reach the prongs of this , this will also send a signal to the gauge to flash at you. My radiator is old and not so efficient so I have ordered a stat that will start to open a bit sooner for mine .

Thanks for the reply. The gauge starts normally and rises over a period of time like a normal gauge should but I think it is reading too high if that makes sense. The engine I fitted came complete on a pallet and we lifted it into place connected the pipes and wiring. I think I'll remove the old sender from the old engine and fit it in the new thermostat and see what happens. Do you know what the rough gauge readings are? eg half way is roughly 80c etc etc. I will check the wiring to the sender also tomorrow.

Rob

[ghost123uk]

When I put the bodged thermostat in the radiator is warm and the fan cuts in when the needle is about 3/4

That bit ^^^ does point to a faulty stat doesn't it. But your infra red temp readings are a bit odd (low) for the gauge to get to 3/4 and the fan to come on (which is normal behaviour) I would put the new stat in a pan of water and heat it up, monitoring the temp with a "normal" thermometer and see when it starts to open.

Is there such thing as a 2.1 dash pcb?

Not sure I understand you there Rob. Do you mean a different one for a 2.1, or do you mean is there one fitted at all ?
There certainly is a dash pcb on your van, but I don't think the 2.1 one is different (could be wrong), but there are different ones for clock/no clock and rev counter / no rev counter. It's 95% certain from your symptoms that this is not the problem.

Aside = I know this is my "pet thing" on here, but did you check / flush out the bleed ring, the T pieces off it and the other small bore coolant pipes coming off it, esp the rubber one at the rear of the left hand head ? In view of the results with the "modded" stat I am not saying this is your problem, it almost certainly isn't, but those thin pipes and "T" pieces do get blocked up and can cause serious problems.

[syncroandy]

Cheap infra-red thermometers are calibrated against a 'black body' (Physics technical term) and are inaccurate for anything else, by quite a bit, from what I've observed. Try it against a shiny stainless pan of boiling water to check.

Swapping back to the original gauge temp sender makes sense, one less variable.

Also, 2.1 rads are a different part to 1.9, they are thicker.

[AdrianC]

My radiator is old and not so efficient so I have ordered a stat that will start to open a bit sooner for mine .

If the rad's a problem, wouldn't it make more sense to replace the rad?

At any time the rad's lack of cooling will be an issue, the 'stat will be open - so having a lower temp stat won't make a difference.
At temps where the lower temp 'stat is making a difference, the rad's capacity isn't really important.

[1_eyed_jim]

When I put the bodged thermostat in the radiator is warm and the fan cuts in when the needle is about 3/4

That bit ^^^ does point to a faulty stat doesn't it. But your infra red temp readings are a bit odd (low) for the gauge to get to 3/4 and the fan to come on (which is normal behaviour) I would put the new stat in a pan of water and heat it up, monitoring the temp with a "normal" thermometer and see when it starts to open.

Is there such thing as a 2.1 dash pcb?

Not sure I understand you there Rob. Do you mean a different one for a 2.1, or do you mean is there one fitted at all ?
There certainly is a dash pcb on your van, but I don't think the 2.1 one is different (could be wrong), but there are different ones for clock/no clock and rev counter / no rev counter. It's 95% certain from your symptoms that this is not the problem.

Aside = I know this is my "pet thing" on here, but did you check / flush out the bleed ring, the T pieces off it and the other small bore coolant pipes coming off it, esp the rubber one at the rear of the left hand head ? In view of the results with the "modded" stat I am not saying this is your problem, it almost certainly isn't, but those thin pipes and "T" pieces do get blocked up and can cause serious problems.

I have the later type plastic bleed ring. The connection to the top of the thermostat housing was blocked so I will check the T pieces tomorrow. I think your right there seams to be a lack of "engine circulation" going on. I will also swap the senders over to see if it makes a difference. Thanks

[1_eyed_jim]

Cheap infra-red thermometers are calibrated against a 'black body' (Physics technical term) and are inaccurate for anything else, by quite a bit, from what I've observed. Try it against a shiny stainless pan of boiling water to check.

Swapping back to the original gauge temp sender makes sense, one less variable.

Also, 2.1 rads are a different part to 1.9, they are thicker.

The infrared thermometer is UKAS calibrated so is pretty accurate I know this. I will swap the senders over tomorrow. Is the 2.1 rad more efficient at cooling??

[AdrianC]

Is the 2.1 rad more efficient at cooling??

Yes, it will be - thicker will mean more surface area to dissipate the heat from.

But that's probably not going to overcome age-related degeneration. A new thin rad will almost certainly be better than an old, caked thick one.

[Mocki]

You have wired the gauge to the thermo switch . Looks the same, but switches the carb heater ect off when the engine warms up. Gauge is the one at the front .......

[1_eyed_jim]

Update: I've changed both sensors in the housing as well as the housing and cover (someone had used silicone to bodge it together!). Also a blockage was found from the bleed ring to the heater distributor.

The thermostat now opens and the fan kicks in! Happy days!

The gauge now sits at 3/4. Is this normal for a 2.1?

Thanks

[AdrianC]

The gauge now sits at 3/4. Is this normal for a 2.1?

It may be normal for yours.

All it's doing is telling you the resistance between the terminal on the back of the gauge, and the earth at the sender. A couple of bad connections, and the uncalibrated gauge may tell you anything... That's why it's the position relative to normal for THAT vehicle that's important, not any absolute position.

[1_eyed_jim]

The gauge now sits at 3/4. Is this normal for a 2.1?

It may be normal for yours.

All it's doing is telling you the resistance between the terminal on the back of the gauge, and the earth at the sender. A couple of bad connections, and the uncalibrated gauge may tell you anything... That's why it's the position relative to normal for THAT vehicle that's important, not any absolute position.

Ok I understand what you are saying. Thanks for the advice!

[ghost123uk]

Also a blockage was found from the bleed ring to the heater distributor.

And yet another one to add to the list.



.

[1_eyed_jim]

The gauge now sits at 3/4. Is this normal for a 2.1?

It may be normal for yours.

All it's doing is telling you the resistance between the terminal on the back of the gauge, and the earth at the sender. A couple of bad connections, and the uncalibrated gauge may tell you anything... That's why it's the position relative to normal for THAT vehicle that's important, not any absolute position.

After a week of use this is where the gauge sits when fully hot and fan kicking in



This is making me too nervous. I know you said this is where my gauge lives but I'm constantly looking at it! Anything I can do? Perhaps a 80oc thermostat?