Manta B Thermostat temperature rating

[Cone8v]

My thermostat seems to be stuck open, whats the opening and closing temperature if the thermostat for my engine?

Its the 2.0E 81kw , dad said he fitted an 87.5 c thermostat last time and that the 92c one would overheat.
Is this true?

The local shop gave me a 92c one thats listed for my car,still havent installed it. Whats the stock thermostat and which one would you recommend?

[Jessopia74]

No, 92 is not an issue in the bigger scheme. But Google thermostat hole mod, as trapped air in the system is the biggest risk. The hole does 2 things. It allows air trapped behind stat a path out prior to opening and it also helps with pressure differential when stat starts to open/close. Makes it smoother operating if you like to think of it like that. It’s just a small hole though, 5mm is enough 

Edited July 12 by Jessopia74

[Cone8v]

57 minutes ago, Jessopia74 said:

No, 92 is not an issue in the bigger scheme. But Google thermostat hole mod, as trapped air in the system is the biggest risk. The hole does 2 things. It allows air trapped behind stat a path out prior to opening and it also helps with pressure differential when stat starts to open/close. Makes it smoother operating if you like to think of it like that. It’s just a small hole though, 5mm is enough 

Ill try to find it, doubt ill mod it right now since im going on a long roadtrip with the manta.
When dad was driving it with the 92c stat he said sometimes the guage would get really close to the red line and with the 87.5 c one while driving the needle would stay dead in the center,

for me it stays in the center while driving and raises one more notch when idling in high temperatures outside. 

I also notice that my km/h needle sometimes jumps around when i let of the gas and go over a bump. A couple of times my temp and fuel guages shut off and then went back on in a second. 
i was reading about the stabilizer relay and that might be the problem.

just wondering whats better ? 87.5 or 92c ? Have you ever had the needle approach the red line with the 92c stat?

Even if the stabilizer is the issue i want to replace my stat just to be completely sure. 

[Cone8v]

Ok i found the mod. You want me to drill a hole in the thermostat so that there is no pressure difference while the stat is closed and for any trapped air while bleeding the system. If i do that on the 87c stat wouldnt the engine heat up way slower and wouldnt it cool down faster after the stat opens? Isnt that a problem?

[cam.in.head]

the 92deg stat shouldnt cause the guage to go into the red or even near to it. possibly theres an issue with the dashboard voltage regulator ( common issue) or the sender unit .( spade lug on brass unit type)

if i run an 88 deg thermostat i get just slightly under halfway on the guage and just slightly above with a 92degree one.none of mine have any holes drilled.

try the hole mod as mentioned but it shoudnt realy need it and MAY result in a slightly longer warm up time or slightly cooler running temp. but it will certainly help with any air locks ? 

 

and to check if the thermostat is stuck open by any amount try starting the engine from cold and notice if the top hose starts to warm up very soon after. it should stay completely cold until the engine is up to working temp and the thermostat opens. any warmth here before indicates a faulty ,leaking or stuck thermostat.

Edited July 12 by cam.in.head

[Cone8v]

It was the voltage stabilizer.

[cam.in.head]

not that it matters now but one sure way to check the std conventional voltage stabiliser is to tune the radio on medium or long (AM)just off a station into blank space and turn the volume up a bit . then turn on the ignition and listen . after a while you will hear a series of clicks as the stabiliser opens and closes . obviously this won't work with an electronic voltage stabiliser but our cars don't have that type( unless it has had one fitted !)

[Jonathan Pounsett]

On 27/08/2024 at 10:53, cam.in.head said:

not that it matters now but one sure way to check the std conventional voltage stabiliser is to tune the radio on medium or long (AM)just off a station into blank space and turn the volume up a bit . then turn on the ignition and listen . after a while you will hear a series of clicks as the stabiliser opens and closes . obviously this won't work with an electronic voltage stabiliser but our cars don't have that type( unless it has had one fitted !)

Handy trick 👍

[cam.in.head]

yes i thought so ! 

the modern ones give an electrically regulated 10v whereas the old mechanical ones just pulse it on and off causing the guages to constantly be switched on and off but because they are thermal devices you don't see it . 

pretty much the same way as you see 50hz flicker on  fluorescent lighting but not on filament bulbs !