Mr2 Reving By Itself

[adidasandy]

:( Hi all, just bought a MR2 M reg and found that when the car is cold or been running less than 20 mins the revs go up and down very fast, only to 2500 rpm but still I don't like it. The funny thing is I had a mk1 MR2 and it done exactly the same thing?????

Can someone help me out to what is causing this.

Thanks Andy

[System~G]

Same problem for both cars.

There's probably air in the coolant system. Although on a MKI one can get problems with the wax stat too - thus the developement of a manual "choke" for the MKI available on the MKI Club.

A bleed of the coolant system should sort it out a treat. After doing the bleeding, just double check all around under the car for any leaks.

Here's a how-to I wrote for the MKI - not sure how different it is for a MKII:

1] Put your heater controls to warm

2] Remove spare wheel

3] Remove the two vinyl hoses attached to the frame behind the spare.

4] Connect one end of one hose to the heater bleeder plug and tape the other end to the bonnet as high as it will go - do not block.

5] Connect the one end of the other hose to the radiator bleader plug and tape the other end to the bonnet support arm as high as it will go - do not block

6] Loosen the valves on both plugs about three complete turns.

7] Loosen the bleeder vlave on the coolant inlet housing near the gear box about three turns.

8] Add Glycol based coolant to the coolant filler gap (where the radiator type cap was) until full. Wait a few minutes to let level drop and fill again. reapeat as often as required.

9] Squeeze the larger hoses around the coolant filler gap to provoke air out the bleeder plugs. reeat steps 8 and 9 until you're sure there is no air left in the system.

10] When coolant level is aprox just under 1/2 way between the markings in the resevoir tank (clear bottle next to coolant filler gap) add water to it to bring to max level.

11] Close all the bleeder valves/plugs.

12] Replace the radiator type cap to one click-stop (do not tighten completely).

13] Start the engine and run on fast idle for about 3-5 minutes.

14] Stop the engine

15] Check levels in resevior and in coolant filler gap. Repeat Steps 9 - 13 if needed.

16] Once satisfied, replace radiator type cap securely (all the way to end-stop).

17] Run engine again for 3-5 minutes.

18] Top up resevior with water again to "full" mark.

19] Start the engine again and check for any leaks etc...

20] Replace vinyl hoses, spare wheel and plastic covers.

21] Check levels weekly or every 250 miles.

HTH

[Bibbs]

woah, quality detailed reply .. :D

[adidasandy]

Thanks mate, outstanding reply. I will try that today and let you know later. :D