engine cuts out in traffic after engine temp reaches 112+

[thinksmart 0]

I have a 16v 1.8 1992 Jreg with almost 200,000 miles on the clock (110,000 by me, as second owner). It's fine on motorways (engine temp is 104-108), but as soon as in traffic, engine cuts out once engine temp reaches 112+. Local garages unable to replicate problem (let alone suggest a solution) while standing idle...All suggestions, and advice, gratefully received

[Rams 0]

I am certainly no genuis, but to me it would sound like an electrical problem. My theory is that when the temp reaches that limit, the fans would normally come on and start to cool your engine, maybe this connection that normally turns the fan on is cutting something short, firstly to make your car continue to rise in temperature and as a sagety net to not blow your engine up. I could be way off but it does sound logical in a way.

 

Obviously, make sure you have checked your water level and coolant and that you aren't leaking anything.

 

Something could be getting really hot and braking down, lets see what other people think and if they are connected with my theory.

 

Hope you find the problem, you will in the end!

[thinksmart 0]

Have already gone thro' most simple and obvious.

 

Have had the radiator off and cleaned and all fans seem to be working. There is no loss of water or coolant. Have just had engine temp sensors changed so this may provide cure (will try out this weekend).

 

I have also a problem with the computer and its display (and this may be connected?). It periodically returns to zero (is there a simple say, battery, answer to this?).

 

I'm no technical person, so please excuse next question! Is there a fail-safe device which cuts in when the engine (not water) gets too hot?

 

Again, any advice gratefully received.....

[Rams 0]

You should hear the water temperature sensor beeping and rising quickly into the red!! Stop immediately ans seek help.

[thinksmart 0]

Thanks RAMS for quick replies.

 

However, its not the water temp that rises and therefore no bleeps heard. The water gauge seems to be constant and OK???????????

 

Its the engine temp on the computer display that rises to 112+ etc.

[stormy 0]

112 is ok mine sits at about 116 at speed on the motorway rises to about 120 max in traffic!! but fan always drops it back!!! i think about 140 is the danger level!!!

sounds like you could have a blockage in your water system!! if that is not getting very hot but your engine is, the water pump may be faulty or thermostat!!! :shock:

[Rams 0]

You dont mean the opil temperature on the MFA do you? The gage opposite your fule is the water and the MFA is the oil temperature and outside temperature.

 

Please excuse me if you already knew this. I wasnt being funny.

[thinksmart 0]

Yes its the oil temp that I mean when saying "engine temp"

 

Those who look at this please read earlier questions and answers, so as not to repaet ourselves.

 

Its the oil/engine temp that indicates the problem is about to happen and the engine to close down.

 

The water side is fine, but the rad has been off and cleaned and fans seem OK

 

I'm no mechanic or technician, so I don't mind any suggestions (the technical bits will go over my head - anyway, what does MFA stand for?)

 

Again all replies gratefully received

[chuck 0]

I've a couple of ideas.

112 oil temp is by no means hot for a 16v. Basically if water temps stay between 85 and 110, and oil between 100 and 120 you're running fine). But your problem could be either electrical or fuel related. Mine developed an electrical problem recently, but only when hot. The starter would not operate once the temp reached a certain level.

I fixed it by taking all the wires off the starter and alternator, cleaning and abrading connections, and reattaching with plenty of copper grease.

 

The fact that your MFA resets at indicates that the power is somehow disconnecting. Could be related.

If I were you I'd have a go at removing all main connections and cleaning the them. I know that there's an earth connection by the battery to the car body and connects also on the gearbox at the starter, and probably a good idea is the live connection to the coil.

Anyone think of any other good connections to re-do.

 

Other idea is the fuel pump. There's 2, a main one under the car, and an aux one in the fuel tank. Its common for the fuel tank one to pack in. If it does, there will be a loud whine (almost grinding) from the main pump (as it straines to take the load). Will result in either the engine becoming very jumpy, or cutting out. Mine only did this in traffic, and it turned out to be the aux pump. Easy replacement.

 

Hope this helps some, because I know all too well how frustrating it is to be going home in rush hour traffic and being pretty sure there will be some problem on the way (whats the way home with least traffic so's my engine doesn't get too hot?? :lol: )....

[sc16v 0]

Does it cut out at exaclty 112 or at different temps above 112???

Once its cut out does it re start straight away,then cut out again. ???

[Henny 0]

thinksmart just out of interest, the MFA resetting thing, is this on BOTH setting 1 and 2 or just on one of them? The reason I ask is 'cos once one of the values in the MFA reaches its maximum (23:59mins or some strange milage that equals 9999km!) then it starts again at zero for all values in that setting....

 

If it's only on ONE of the 2 settings, then this is probably what's happening... If it's on BOTH settings at the same time, then your dashboard is loosing power from the battery/alternator which is resetting it. If this is the case, and it's resetting when the engine stops in heat, I'd check your alternator as it could be a connection in there that's breaking down with temperature, shorting out and causing a lack of electricity to the engine which is causing the stopages.... :?

 

:?: Will the car start again after it's cooled down a bit, or do you have to bump/jump start it? If it starts as soon as it's cooled then I may well be talking rubbish as your battery hasn't gone flat which would suggest a connection fault, not a short...

 

Hope you find out what's causing it.... let us all know if you do... :)

[thinksmart 0]

Thanks for all of your interest and all of your replies.

 

Chuck's ideas, I think, will be very interesting, as I do have a serious whine from the fuel pump at the same time as the engine/oil temp rises in traffic.

 

The MFA zeros on both sttings so it's probably to do with connections as suggested.

 

As a general reply, the engine (or whatever is the real problem - fuel etc) needs to cool down before it will restart. It doesn't need to be bump started.

 

All ideas will be followed up (my brother-in-law - very experienced with performance cars and VWs - maintains my car, but he's in South Yorkshire, so all of these ideas will be passed on as soon as I get the C to him).

 

Thanks again.

[Joe M 0]

I had a similar problem in my old 16v, although it happened at nearer to 90. It turned out to be the hall sender in the distributor that was knackered, replaced this and all was fine.

[Joe M 0]

In fact I meant to say I had to replace the whole distributor as it was a 2.0 16v, but I think the hall sender can be replaced seperately on the 1.8

[thinksmart 0]

Thanks Joe M, I'll add this to the list of possible solutions. The only thing I've got to decide now is the order in which to try things out (simplest/cheapest first I think)

[chuck 0]

For info (cuz its yet another thing I've replaced recently)

Hall sender is £80 odd plus VAT from VW (and is a bollacks to fit apparently - you need to separate a few clips/seals and renew them -of course VW don't know which ones!!).

Complete new Bosch dizzy from Euro car parts is £75 ish on an exchange basis. Simple "plug and play" as they say.

[thinksmart 0]

Thanks Chuck for the info (do I sound like Cilla here????)

 

Wish I'd found this site before (thanks to Edwina for her lateral thinking), it would have saved a lot of messing...

 

Again all replies gratefully received........