I love cut and amp; paste
Noisy Tappets
Cars affected:
All hydraulic tappet cars (Lancer 1800 RS/GSR, Evo 1-7)
Symptom:
Loud 'ticking' noise from the top of the engine after starting from cold. Rises with engine revs however it should go away.
Problem and cure:
The 'ticking' noise is most often caused by air being trapped in the Lash Adjusters of the hydraulic tappets. The air is compressed in the high pressure chamber of the Lash Adjuster and therefore the adjuster does not take up the clearance between the tappet roller arm and the cam lobe correctly when the valve is opening. It may take a short period for the air to be expelled after starting the engine so some 'ticking' is acceptable, however if the noise lasts for a long period or doesn't go away at all then there maybe a problem.
Air can be trapped in the adjuster due to several reasons that are listed below:
Incorrect grade of oil used (too thin or thick).
Old oil (debris in the oil may block an adjuster).
If the car is stood for a long period or if it is stood on an incline (the oil will drain from the adjusters).
Over filling the engine with oil (if the oil level reaches the crank it may churn air into the oil that will migrate to the lash adjusters).
If the tappet noise does not disappear soon after start up (5-10 seconds) then try some mild racing of the engine. Gradually increase the engine speed to 3000rpm (over 30 seconds) and then gradually decrease it back to idle (again over 30 seconds). Repeat this roughly 10 times. If the tappet noise disappears then the air has been expelled from the Lash Adjusters and they are working normally again. It is worth checking your oil level and condition as that maybe the cause of the air entering the Lash Adjusters in the first place. Change your oil if in doubt. Make sure you use the correct grade of oil as going too thick or thin can make matters worse. Mitsubishi quote 10W30, it is not recommended to use 0W or 5W rated oil. If an oil change makes no difference then the adjusters maybe blocked or damaged and will require cleaning or possible replacement. This can be done by a competent home mechanic or if in doubt consult your servicing agent.
Approximate cost of repair:
Oil change |EQU| £30-£50
New Lash Adjusters are approximately £18-£20 each inclusive (fitting approx. 2-4 hours depending on the number to replace).
Good point about the oil filter though, I have heard it mentioned before with the earily Evo's (1-3). I didn't realise there was more than one filter for the E6 or a confusion over what one to use? Obviously there is.
I will add that to my list.
Anyone know the correct part numbers for the oil filters on all the Evo's? (my E6 has been fitted with MD322508 every service for the last 18 months)