Hello fellow members, I trust you are all well and Navidad ready. I could use some help. I have two pressing problems that may have connections. The first is my temperature guage rarely works, mostly doesn't but once or twice works for a few minutes. The second is at traffic light lights etc the car "hunts" (?). This is to say, the revs rise and fall between 750 and 1800. Aside from the fact it nearly stops the motor and the car shudders, it makes me look like an attention seeking weirdo. Save me forum, what do I need to do? Thank you in advance.
First thing to check with hunting is air leaks. If you haven’t already, check all vacuum hoses and pipes. The temp gauge issue sounds like a loose connection. Could also be heat related, ie it works when heat makes a connection expand. Have you tried a new sensor?
Thank you for your reply. I will check the wiring and then send it to have the sensor changed etc. It will have to wait now until everybody returns to work on the 8th.
What engine/car is it? if it's a PB mk2 8v digifant there is a grommet in the rocker cover where the breather/isv attaches to. the grommet can split and cause an air leak
It’s an ‘88 8v according to your introductory posts. Is it the original engine? Take some pictures and post them up, sometimes people can see something that isn’t right that you might not have noticed.
It will be nice to know what type I have at the least. I should also point out that sometimes it doesn't hunt, just sits nicely as it should, albeit a little high. Again, thanks in advance.
You're in North / South America? I think your car may be the PF engine, basically the same as our PB version, but with the addition of a catalyst and its own ECU. If you have the paper sticker on the inside of the boot / trunk / hatch area, close to where the rear lights are fitted, it will confirm the engine code. If the sticker wasn't used outside of Europe or is missing / damaged the same code along with the engines number will be stamped on the cylinder block, situated just out of sight in your image, below that coolant pipe. The rubber grommet referred to is just in sight on the rocker cover.
Apologies, don't know why I thought you were from the US! Anyhow, you should hopefully find the 2x letters in one, other or both of these places that'll answer your question.
Great, a PB then. If you're interested and have the time there's lists on line and possibly the forum too of what most of the various option codes denote. AUG is your gearbox code and 5G means 5 speed. L90E is Alpine White. Where you see 49 on my sticker, that's the interior trim spec., which is Rainbow in my case, but yours is obscured in the image.
Just to update in the hope it helps somebody in the future. My mechanic changed the two temperature sensors and the hunting has stopped. Now sometimes it idles a little high, around 1200 rpm and sometimes a little higher still. More work needed there then. On a side note, the temperature gauge still rarely works and when it does decide it wants to play ball it reads low when the car is clearly up to temp. It sits at around a third of the way up and the fan is kicking in so I would think it should be around halfway. The mechanic says buying second hand clocks could be a waste of money as they could be worse. So, my question is regarding an aftermarket temp gauge. What is a really reliable brand to go for? I hate buying cheap rubbish and Chinese products. All advice gratefully received. Thanks in advance.
I also had issues with my temp gauge being unreliable and finally completely broke. Firstly you can usually test the gauge by simply grounding out the sensor wire with the ignition on. When grounded the gauge should shoot up and go off the scale with the temp light flashing if your gauge is OK. If not your gauge is kaput and you need to replace it. Or your wiring from the engine bay to the gauge is dodgy … so also worth double checking this for continuity. You can get replacement gauges to replace the unit in your cluster. For my 16valve I got one from Volkswagen classic parts which I believe are based in Europe. To replace it I had to remove the gauge cluster and disassemble from the back side. It was fiddly and a bit nerve wracking but went back together ok and now fully working as your mechanic said I would guess a second hand set of clocks is a bit hit and miss as I imagine they are all coming up to an age where they may start to have issues plus your mileage /Kms will be out as well so I would prefer to stick with the original if possible. It’s also a great time to replace the bulbs for the backlight whilst your in there now I can see the gauges when I drive at night which is a huge improvement
start here: https://clubgti.com/forums/index.ph...ose-and-tune-your-mk2-digifant-gti-8v.124949/ just to add the dash temp sensor is the black one, and the plug has yellow/red wire. ecu sensor is the blue one. they're not the same either, so make sure you dont mix them up and buy the right part numbers!
Thank you kindly. The mechanic changed both sensors and I would hope he got them correct. Iay show him this guide one day when we have plenty of time to go through it, I know much people have said how useful it is.
