Hi all,

Wonder if anyone could confirm the following for me:

Am I right in thinking that the GTM / ETB oil pressure and water temperature gauges required bespoke sensors to run them and not the original rover items fitted to the water outlet (blue plug) and oil filter housing?

I have a rebuilt MG ZR VVC 160 engine about to go in as a replacement for the current lump with a blown head gasket which I think was from an MGF (160) and the original unit has a sensor in place of the original Rover blue water temp sensor which I think drives the gauge - presumably I need to cut of the blue plug from the MG ZR engine loom and adapt to the gauge sensor?
On the oil pressure side I think the MG ZR filter housing has a oil pressure switch in it that illuminated a warning light in the original MG and this needs to be replaced with a sensor to drive the GTM / ETB gauge - is this right? The current engine has such a sensor in the filter housing along with the original Rover switch which I presume wasn't connected. Again I assume that I need to cut the MG ZR oil pressure switch plug off the engine loom and connect to the gauge sensor?

I can't refer to the original MGF engine loom the car had as it was stripped out by the previous owner.

Back to the oil pressure gauge - my car does not have a low oil pressure warning light, just a gauge (unless there is a warning light in the gauge but I can't see one). Is it possible to have a low oil pressure warning light as well? My car has the GTM supplied Mems3 and 5AS looms and from the look of the connection diagram I have, only has provision for a gauge. Would I have to run a wire from the switch back through the car to provide a warning light or is there provision in the GTM wiring for one somehow?

Appreciate any advice on this one chaps.

Cheers, Jamie

I used the water temp sensor that came with the MGF engine and it seems to work fine with the GTM gauge. For the oil pressure I bought a cheapo sender off eaby 0-10 bar and it works fine with the gauge too. Check the thread. On mine its a metric 12x1.5 from memory but most senders seem to be npt.
Lack of warning light is an issue. Many senders have a switch connection for a light to but I think they are often set quite low, just 7psi, so a bit late. I was thinking about a 15 psi early warning light. Might flicker at idle but would shout at you on a track day. Would then need a separate wire, sender and light. Having lost big ends from oil starvation this is a worry of mine.

What are you doing with your old lump? I could do with a 160 bottom end to rebuild over the winter.

hi Jamie

on my mems 3 engine i have two oil switches on the filter housing.
one is for the warning lamp oil pressure like on all car as you turn on the ignition switch light comes on and goes out when you have pressure

the second one in the oil housing is a variable temperature sensor this is for the oil temp gauge this is a electronic sensor .
as far as i could work out from the diagrams the same out put from the oil temperature sensor went in to the instruments for the hight oil temp warning light
in the mgf speedo cluster there is a electronic board in side it ( INSTRUMENT WARNING LIGHT PANEL see file ) this has the illuminated warning led on it
I think you would need this part the make a light come on




paul

Hi have just read this again you was asking about pressure not temp



if you are looking for the oil pressure waning light if you have the 2 sensors at the oil filter then you could change the temp one for pressure for the gage and use the over one for the pressure light

i hope i got this right
Regards paul

Thanks for the advice chaps.

Sanz - so if the standard 'blue' rover water temp sensor on your engine loom runs the GTM gauge I'll give that a go first and if for whatever reason it doesn't work I can always switch to the GTM / ETB sensor in the current engine. Also, sorry but I'm going to keep hold of the current engine as the bottom end has only done 30k and it'll be my back up. Did you see the one that went for about £90 on eBay this week - I just missed out on it

As for oil pressure (Paul, I've sent you a PM so this bit will bore you ), the current engine has the GTM / ETB sender which on looking at the ETB website also has a terminal which is a built in pressure switch. However, it's set to 7 psi which is too low as you say.
I think what I'll do is use the current engines filter housing which has an ETB sensor (and an original pressure switch) to run the gauge, hooked up to the engine loom wiring, and then buy a replacement pressure switch from Elise parts which is set to 14 or 15 psi and run a new wire back to the dash for a warning light. Best of both worlds then, don't like the idea of no warning light

No worries

Good luck with the gauges. Where will you mount your early warning oil pressure light? If for track use it needs to be somewhere right in your face! Was it Kano Nordie who suggested using a 2" land rover stop light?

hi
you have me thinking now
I have no temp or pressure gauge
i do have the mgf temperature sender in the oil filter but i did not use it as i have no gauge
i think it would be good to have one but which one temp or pressure
it would simple to have temperature as all the wires and sender is in in place
but is pressure better
i do have the mgf low pressure switch with light

Some oil filter mounts have two tapped holes, others just one. My ex-MGF VVC engine has two and came with a pressure switch and a temperature switch - both only intended to trigger warning lights. The current VVC engine I have in was from a Rover 200BRM and only had the pressure switch (which I replaced with a gauge sender) with the other tapping undrilled. I'm guessing the difference is because oil temperature is more likely to be an issue with a mid engine as there is plenty of air flow for the front engined car to cool its sump directly.

As I've now fitted an oil cooler fed off a sandwich plate I have a couple of spare tappings on the sandwich plate for extra senders so I've fitted an oil temp gauge too. As such I now have oil temp and pressure gauges but still no oil pressure warning light! I have one more tapping that I could use for that one day if I want an early warning one or I could use the switch connection on the gauge sender.

Not sure where I'm going to put an oil pressure warning light but it needs to be near the instruments sonewhere so I can see it before it's too late not sure I can fit a Land Rover taillight between the gauges though

Contrary to what I said earlier, I think the rover sensor / switch in the current filter housing is probably for oil temperature rather than pressure as it's an MGF housing and the other tapping has the ETB sender. I'll replace the temp sender for a pressure switch from Elise parts so I have a gauge and a warning light. I can always fit a temp sensor at a later date if I want (you can buy an adaptor to fit two senders in one tapping) but it's pressure I'm after for now - both is ideal obviously.

SANZ - do you know what the pressure switch is set to in your sender unit? On the ETB one its 7psi which is too low in my opinion.

I don't actually know but I'm sure I read somewhere that they are generally set to 7. Mainly to avoid people getting worried by the light flickering on a hot idle. If you do go for a 13 or 15 early warning it will come on at low revs from time to time but nothing to worry about.

Yeah, I think the Elise parts switch is set to 13psi and I could live with it flickering at idle occasionally I think, it might get a bit annoying though.
I think 7 psi is too low though, if it came on at 7 psi when you were giving it the full beans it might already be too late.

Or I might get an adjustable one and set it at about 11 psi....

Off topic - does your 160 engine have an oil cooler as standard? I was looking at a TF 160 engine which does have one, an oil to water heat exchanger on the back of the block. It looks like its mounted where the coil packs are on a mems 2 143 so might be an issue if (as I was planning) I get a 160 bottom end only - if all 160's have oil coolers then I might go the whole hog and go for a whole 160 engine and mems 3 as I do like the idea of an oil to water cooler as TBH the oil to air one I've fitted isn't ideal.

It depends on which car your 160 vvc came from as I think only the MGF had the factory water to oil cooler

My car currently has a MGF trophy engine and it isn't running the cooler, the new engine is from a MGZR and doesn't have one either. It's only the coolant pipe work under the inlet manifold that's different anyway so you can retro fit a factory one if you'd like.

However, I'm fitting a laminova cooler to the new lump when I fit it in and won't bother with the factory one - you could do this on yours whatever bottom end you have so it wouldn't be a problem to leave the coil packs in their current position.