Throttle Housing

[T42]

Looking for a throttle body housing for MX5 1.6 . Engine running too fast on idle 1000-1200 rpm. Mechanic suggest a replacement throttle body if anyone knows someone with one greatly appreciated.

[sidewaysreilly]

ask him why its the throttle body..............may just need a clean

[T42]

Mechanic did'nt suggest cleaning throttle housing! He did a pressure test and checked over the car for a few hours and could'nt figure out why its overheating on motorway drives. His theory is the high revs at the throttle housing which would be fixed by replacement! His 2nd theory is the head might be damaged. His alternative suggestion is to wire the AC fan to run from a switch on the dash as a second fan and use a lower temp switch so the main fan comes on sooner.?

[charged_rs]

high idle = idle speed control valve - get it checked

overheating - flush your rad / coolant , replace thermostat and check condition of thermoswitch ontop of thermostat housing.
Is your rad old ? its possible its partially blocked esp if its a green/brown colour.
A new rad should be black , - over time the colour changes , closer to brown it is then its really old- its the heart of the cooling system so i would advise you to change it , then atleast you know its good and its doing its job 100%

only if you have severley overheated would your head be damaged / warped., ie its overheated and you didnt notice. Power would be down considerably and youd be loosing coolant.

[T42]

Rad is old alright...Olive Green. Rad was flushed thermostat changed and now removed. Still overheating, only keeping it cool with heater fan and AC but still too hot on motor-way over 80-100kph. All cars fly past as I try to keep engine cool at a lower speed.

[sidewaysreilly]

its not your throttle body, thats for sure.

[leamyj]

Trouble with sensors maybe??? Has the car been diagnosed?

[T42]

How or where can I get a diagnosis. The 1.6 is a 93 import. Do I have to go to Mazda or is there a better option?

[sidewaysreilly]

get a garage to pressure test your cooling system and make sure its bleed proprely.

[leamyj]

How or where can I get a diagnosis. The 1.6 is a 93 import. Do I have to go to Mazda or is there a better option?

There is a simple method of reading fault codes using a LED...see www.mx5parts.co.uk , they have a booklet and LED for sale at a reasonable price. Alternatively, if you google mx5 mk1 fault diagnosis, it should throw up more info.

John

[Fergus]

Just read this now and shocked nobody stated the obvious
Get a new mechanic !!!

[sidewaysreilly]

true Fergus. You really need to pressure test the system. This will check the rad cap and the rad, pipework, heater matrix . It could be as Paul says a bunged up rad. Try draining and refilling with a good engine cleaner. Keep us posted.

[T42]

Had the pressure test and all is good, no problems. Think I will get a new rad as it might solve the problem.

[T42]

Changed the radiator to eliminate it as a source of the problem and its solved the problem. No mechanic required and I will be changing the mechanic who said its the throttle housing. thanks for all yer help. Appreciated!

[sidewaysreilly]

your welcome lad.