Hi, i've noticed that my motor has developed a bit of a ticking noise at idle, and i was wondering if this is normal, and if its not normal, what the noise could potentially be.

I'ts pretty clear is valvetrain related (tappets/lifters)? but apart from that im out of ideas.

Background on motor is JDM spec, approx 78,000km with 8,000km of those clocked up by me. Over this time its been well looked after, with 5,000km services, warm up/down periods and decent oil (Motul). It is due for a service in 500km but i doubt this is going to be the cause...

Any help appreciated.

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Tim // Melbourne, Australia

1986 ST165. 148,000km on chassis
ST205 WRC engine / IC system / rear LSD 78,000km on engine
Aussie 3" dump pipe/3" system
TWM short shifter.
Whiteline strut brace

If it's definitely valvetrain then it's almost certain to be a valve clearance gone out of spec.

Mine has similar issues although the noise is now getting louder and starting to sound much more concerning

Unfortunately there's no simple cure for this although the problem is easily solved

The 205 head uses a shim under bucket arrangement to set up valve clearances. Think of it like this

Take an ordinary house bucket and turn it upside down. Then place this on top of a bollard. This is basically the same arrangement as the tappet and bucket in the 205 head

Then picture the cam at a fixed distance from the top of the bollard. The only way to change the distance from the bucket to the cam is to make the bucket floor thicker. In the 205 this is done by placing a circular shim between the bucket and tappet.

What all this means is that when the clearances go out of spec you'll need to removce the buckets in order to change the shims (after measuring up everything first lol). It's not a hard job per se but it's a bit specialized

Mine makes quite a rattle at idle, but it goes away when I turn off the aircon soi've never bothered to sort it

Maybe you have the same?

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JDM ST205 (286bhp and 281lb/ft)
JDM ST202 (Finally sold )
1982 Pontiac Trans Am 5.7L V8 (See my website)

The "tick tick" on the 205 is the fuel evap system. A valve appears to be pulsed when at hot idle - sounds bad but seems to be very normal.

Of course this "tick tick" noise may not be the root cause of everyone's "tick tick".

Knock knock is more serious

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Kris
95 ST205 - slept for 10 years, now waking up...
Avensis
http://www.gtfours.co.uk
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Turbocharging - the replacement for displacement

I had a tick-tick noise on my Four and it turned out to be a knackered air-con compressor clutch. I think I had over-tensioned the drive belt

Given the possibilities in the above thread you could try and narrow down the search using a stethoscope or the lower tech equivalent of a large screwdriver as a probe held to the ear. This works surprisingly well!

HTH

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Don
GT4DC Chairman
1994 Toyota Celica GT-Four ST205WRC JDM 269bhp @ 0.9bar
1994 Toyota Celica GT-Four Special GT 590bhp @ 1.8bar
1989 Van Diemen RF88/89 Formula Ford 1600
2008 Nissan Patrol GU 3.0L ZD30DDTi 154bhp

Thanks for the quick replys guys. I think Kris nailed it though, as it doesn't sound particularly serious and it seems to only happen when the car is warm.

Its definitely a tick and not a knock though, fortunately.

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Tim // Melbourne, Australia

1986 ST165. 148,000km on chassis
ST205 WRC engine / IC system / rear LSD 78,000km on engine
Aussie 3" dump pipe/3" system
TWM short shifter.
Whiteline strut brace

Mine ticks like a mutha on hot idle, is fine otherwise tho.

I thought it was either injectors or valve clearance.

Not worried about it really.

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Chris
ST205 with a little help from a ST215...

Reason i got concerned was i was reading an article about 2nd hand WRX's and they said that loud valvetrain noises typically herald the beginning of the end.

I underestimated the strength of the 3S obviously!

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Tim // Melbourne, Australia

1986 ST165. 148,000km on chassis
ST205 WRC engine / IC system / rear LSD 78,000km on engine
Aussie 3" dump pipe/3" system
TWM short shifter.
Whiteline strut brace

Never underestimate the power of paranoia

The amount of "What the heck is that noise" moments I've had because a diesel has pulled up 5 cars behind me at the traffic lights