DIY: Valve Clearances - 4G15 and 4G93

donki

Administrator
Forum Administrator
4G15 and 4G93 factory valve clearance specs:

-Adjust when the engine is hot, and when rockers are not rocking.
-Rotate engine by hand so cylinder 1 is at TDC of compression stroke.
-Adjust the clearances as follows to the specs below:
Cylinder 3's intake
Cylinder 4's intake
Cylinder 2's exhaust
Cylinder 4's exhaust

Intake when hot: 0.2032mm
Exhaust when hot: 0.254mm

When Cylinder 4 is at TDC of compression:
Cylinder 1's intake
Cylinder 2's intake
Cylinder 1's exhaust
Cylinder 3's exhaust


4G15:
Intake when hot: 0.2032mm
Exhaust when hot: 0.254mm

4G93:
Intake when hot: 0.200mm
Exhaust when hot: 0.300mm


Dont mess it up, cause if theyre too tight, you're car will sound like a v6 with a cam, or if its too loose it will tick like an old VN
References:
valveclearanceqb1.gif

(Intake cold 0.1016mm, Exhaust cold 0.1778mm, if you want to experiment and try these with the engine cold)
 
Last edited:

th0m0mx83

Active Member
Re: Valve Clearances - 4g15

So what your saying is.......... do it to tight so it sounds like its better then it really is? :p
 

donki

Administrator
Forum Administrator
Re: Valve Clearances - 4g15

th0m0mx83 said:
So what your saying is.......... do it to tight so it sounds like its better then it really is? :p

Yes :troll:



Too tight will mean the valves dont fully close, pumping fuel and air into the exhaust, and back into the intake. Sounds cool-ish, but it will burn out your valves and thats a bad thing
 

nikm178

Member
I did this :thumbdown: first time adjusting valves haha soooo regretful lol car ran fine i touched them to get rid of what sounded like a noisy lifter but instead i made it worse lol :crazy:
 

donki

Administrator
Forum Administrator
Are the 4g15 specs listed here are correct for the dohc 16 valve 4g15 as well?

I'm not sure, i do know that the 0.200mm and 0.300mm is a relatively standard valve clearance for any engine, so it would be a good starting point. You can then closer or open the gap if the car is too noisy or lumpy afterwards.
 
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