Jump to content

Temperature gauge


Recommended Posts

Ok, so i can guess how the first part of this will go. 'Dont rag it', 'get a gauge that reads in degrees, not apples and pears' so if we can avoid that, that would be great. I wasnt ragging it and this is the gauge I have for now.

Any idea when the needle is too hot? Normal is at 12 o clock on the motorway, but today it moved a fair bit to the right - still in the white though (the other half got the photo):

1.thumb.jpg.de3c9eca2da38e2879cca4cfbeaea75f.jpg

The needle didnt go any further than that, but apart from a few times on steep climbs in the south of France last summer, it never moves beyond vertical. Outside temps were 30C+ on the 250 miles just traveled. Speed 70-75. The gauge initially climbed on a steep incline on the A30 in Cornwall. It never went into the black or red though, so i assume all is ok? Any one any ideas what the temp difference is between vertical and where it is in the pic?

 

Second part is what gauges do those of you use that have swapped out the standard one for one that reads in degrees? I cant afford the expensive one that mmgemini always points towards! Finally (so a third question), what thread sender unit do i need to order for my defender 200tdi?

Link to comment
Share on other sites

It's been pretty hot today, so it isn't surprising. I would suspect some part of the cooling system isn't that efficient. Radiator/water pump?

I had my radiator explode just cruising on the motorway on a 30 degree day. There was too much mud in the fins, but had been fine until the ambient temp went up.

Link to comment
Share on other sites

Thats partly whats puzzling me. The rad is a recore about 2 years old. The coolant is only about 2 years old bit is the correct level etc. Water pump is old (I have never replaced it and that engine has been in for 9 years) but surely the water pump either works or not or do they become less efficient?

Link to comment
Share on other sites

Worth looking into the fan too if it's anything other than a fixed blade belt driven type, viscous couplings have been known to stop engaging with age, and electric fans failing to cut in because of a failed temperature switch is the breakdown service's favourite summer call-out.

With that type instrument "too hot" is when it reads significantly higher than usual wherever usual is,  I'd stop and investigate if it ever went into the black.  Vehicle temp gauges are not exactly precision instruments regardless if they're marked in degrees or coloured sectors, add in that the sender tends to have a tolerance of +/- 10% at manufacture and drift as they age. Even the best senders are only +/- 5% then the instrument voltage regulators also vary. The result is a situation where it's blind luck if two vehicles read the same at the same actual temp.

  • Like 1
Link to comment
Share on other sites

Thanks. 

Fan wise, I did look at it in this thread: 

 but the fan i bought was seized on permanently.

However, all of the temps yesterday were 50-70 (I didn't stop on the journey), so I would have thought air flow through the rad was good the whole time.

I might replace the water pump to be sure it is in good order (I can't remember, can I do this on the 200tdi without stripping the timing case?)

Finally, gauges. This one: https://www.merlinmotorsport.co.uk/p/vdo-water-temperature-gauge-310010002 and this sender: https://www.merlinmotorsport.co.uk/p/vdo-water-temperature-sender-5-8-unf-thread-323801001008 should do the trick???

Link to comment
Share on other sites

9 hours ago, reb78 said:

Thanks. 

Fan wise, I did look at it in this thread: 

 but the fan i bought was seized on permanently.

However, all of the temps yesterday were 50-70 (I didn't stop on the journey), so I would have thought air flow through the rad was good the whole time.

I might replace the water pump to be sure it is in good order (I can't remember, can I do this on the 200tdi without stripping the timing case?)

Finally, gauges. This one: https://www.merlinmotorsport.co.uk/p/vdo-water-temperature-gauge-310010002 and this sender: https://www.merlinmotorsport.co.uk/p/vdo-water-temperature-sender-5-8-unf-thread-323801001008 should do the trick???

Those are the correct items to change the gauge and sender.  Make sure you run a new dedicated wire from the gauge to the sender and make sure the ground connection are all good (engine to chassis, main loom to bulkhead, battery to gearbox) as any of those wiring problem make the gauge read wrong.  Buying an IR temperature gauge goes a long way to answer if it is really getting hot or it is the gauge.  It is best to actually troubleshoot and not randomly toss parts at it.

Link to comment
Share on other sites

Well, VDO gauge fitted and, if anything, things are a little cool! This was after a run on the motorway and then a couple of miles back through town and idling on the drive. The second pic is a thermal image camera and the temperature is at the gauge sender in the thermostat housing.

VDO.thumb.jpg.021525193ac05fdb7153341f85b99743.jpg

 

Temp.thumb.jpg.1b0613b780ce3ee1f4691b0b0c03404c.jpg

It seemed to get up to about 84/85C on the motorway on the gauge.

 

Link to comment
Share on other sites

I'd say that new VDO temp gauge is spot on correct going by the thermal image temp reading, May just get the same temp gauge for my 200tdi as the Td5 version doesn't seem to move very much. I feel a phonecall & visit to merlin motorsport at Castle Coombe during this week, as I know they are a VDO vision gauge stockist.

200 & 300Tdi engines are cooling running anyway.

Link to comment
Share on other sites

I was worried it was under reading initially, but like you say. Spot on. You reckon those temps are ok engine wise?

The gauge and matching sender came from Merlin Ralph.  Best price I could find and very quick postage too. About £50 all in. 

Link to comment
Share on other sites

So. I think the comments re the stat are correct. 150 miles done today. On warm up, you can see the gauge rise to just over 80 and then the stat opens and it drops to about 77/78. If you pootle along, that's where it stays. If you put your foot down on the motorway, it gets to about 82/83 but no higher. 

  • Like 1
Link to comment
Share on other sites

Richard, mine did this a few years ago. It turned out to be a bad earth on the gauge. No doubt the VDO gauge is better than the original one you removed, but I wonder if a bad earth may have been a factor which you disturbed when fitting the new guage?

Link to comment
Share on other sites

Thanks Phil. Not sure on this one. I may have disturbed something, but the raise in temp indicated in the original post definitely coincided with a hard run up a hill. Probably didnt even get to 90C looking at the VDO gauge!

It wont be getting any attention for a while though - lost all gears again this morning, so its looking like the boxes need to come off AGAIN! (will update my other thread on the issue on this!)

Link to comment
Share on other sites

On 6/25/2017 at 8:56 PM, Retroanaconda said:

Might be worth testing your thermostat. Or for all the cost of them changing it for a known good one.

I had to go through 4 thermostats before I found one that worked correctly, one Allmakes, one Bearmach, and two LR Original parts. Last one was LR and its perfect.

Link to comment
Share on other sites

  • 3 years later...

Hi all

I'm having a delema with my cooling system on my defender, my heater was blowing Luke warm air so I decided to change the thermostat ever since this my temperature gauge shoots up to the red after about 3-4 miles. He engine doesn’t seem like it’s over heating I have checked for air locks, there’s no oil in the water, any thoughts please 

thank

Marty

 

 

 

Link to comment
Share on other sites

40 minutes ago, Martyshutts said:

Hi all

I'm having a delema with my cooling system on my defender, my heater was blowing Luke warm air so I decided to change the thermostat ever since this my temperature gauge shoots up to the red after about 3-4 miles. He engine doesn’t seem like it’s over heating I have checked for air locks, there’s no oil in the water, any thoughts please 

thank

Marty

 

 

 

What engine have you got fitted? Certainly sounds like an air lock  

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy