Tappet cleaning guide

[CJ]

Taken from Club VR-4 Articles section (closed access), certainly worth a try if you have noisy tappets (aka lash adjusters or hydraulic lifters).


Curing the Clatter: Lash Adjuster Air Bleed


Difficulty level
My Granny could do it!


Time to Complete
Less than 15 Minutes


Tools Required
1x Right Foot
Patience


A common problem with galants/legnums is the development of a diesel-like clattering noise on startup.

This is often (correctly) ascribed to the hydraulic lash adjusters aging - either the internal spring starts to fail, or the oil channels become silted up with debris.

There is however another cause - an airlock in the lifter's high pressure chamber - which is very easy to cure.

Anything that allows excessive air to mix with the engine oil can cause this:
Overfilling with oil - allows the crank to churn up much more oil and mix it with air
Low oil level
Degraded oil - air does not separate from the oil effectively as the oil ages and breaks down
This can result in a 'bubble' of air becoming trapped in the lash adjuster's high pressure chamber - the bit that should normally fill with oil. As air is much more compressible than oil, it effectively makes the adjuster more 'spongy'. A bit like air bieng trapped in your brake lines giving you a spongy pedal that needs to be pumped several times before it works.

It is easy to fix, and well worth a try if your car is starting to clatter.

Warm the car up to normal operating temperature.

With no load on the engine (ie be in Park or Neutral), repeat the following process around 20-30 times:
Over 15 seconds, gently increase RPM from idle to 3000. When you hit 3000 rpm, quickly release the throttle.
Wait 15 seconds and start again.
15 seconds is going to feel like a long time! A single cycle will take you 15+15=30 secs, so 30 cycles is going to take 7.5 minutes.

You should find that the noise disappears completely during this process. Once it has gone, you need to do another 5 cycles. I'd suggest doing at least 20 cycles.

Leave the car idling for another 3 minutes before switching off.

You may be lucky, and find your diesel-immitating car is cured!

[steelroe]

http://www.myrollingroad.com/hlacleaning.pdf

[lewisdale]

would this work the same way on my 1995 fto gr?

[steelroe]

In a word yes but all depends if the tappets are worn or just dirty.

[lewisdale]

well today i done the tappets on the front head, every single one was seized solid, manged to free them up and stuck them back in after soaking in oil, rattled like feck for about 5 mins and wouldnt seem to stop so went for a drive and after a couple of miles they went quiet, planning to do the others tomorrow depending on what it sounds like from cold

[Kace]

Good job - how long did it take you ?

[lewisdale]

roughly a hour and half including cleaning then, but obviously the tappets on the rear head will prob take about 2 hours as inlet manifold has to come off

[lewisdale]

decided im not going to do the tappets on the back head now, started it this morning and it was lovely, no noisy tapping,
so just doing the front tappets sorted it

[Dave1971]

[quote="lewisdale"]decided im not going to do the tappets on the back head now, started it this morning and it was lovely, no noisy tapping,
so just doing the front tappets sorted it[/quote]


Was your motor a manual or a tip, as it advises to rock the car back and forward so the cam rotates. Not sure how you would do this with a tip.

[lewisdale]

its a tip, just put a spanner on the nut on the end of the cam pully and turn the cams like that

[Dave1971]

I thought so but its better to ask..

[steelroe]

[quote="lewisdale"]its a tip, just put a spanner on the nut on the end of the cam pully and turn the cams like that[/quote]
Would not advise that you could easily jump the wiming. Better to turn at the crank pulley. Use a long extension bar.

[MY-JAP-MISTRESS]

how long is this ment to last?? i chqanged mine last year so dont really have to worry about it again but for people who do this how long will it last before they actualy have to go out and buy new tappets

[lewisdale]

im not sure to be honest, how longs a piece of string? if the tappets arent worn its a long term fix i suppose as it was just a case of cleaning and unseizing them