Valve Lash Adjustment

[5sfeCelica]

hey guys/girls i recently blew the head gasket in my car 92 celica gt (5sfe) and finished everything up last night and when i went to start it cranked up perfect and idled great but is ticking in the head. I was wondering if anyone had any advice on adjusting the valves on it i would really like to do it myself since the dealership wants almost 600 bucks to do and i cant afford that at the time any information would be great thanks in advance

[93celicaconv]

Sounds like you didn't take the head apart to put in new valve seals, and to machine the headgasket surface so it was perfectly flat before reinstalling the head? I would have recommended you do that, especially the machining work, because if the head's mating surface to the headgasket isn't nearly perfectly flat, you will likely have headgasket problems surfacing again in the future.

There is a complete service manual for 5th Gen Celicas on www.celicatech.com. I would recommend you go to that forum, get to the 5th Gen Celica service manual, and go to pages EM-22 to EM-25. It will show you exactly how to measure valve clearance and how to calculate the new, replacement shims you need to order to get your clearances back within spec.

Did the valve train ticking just start happening after the headgasket change? If so, I would check the torque on all the cam bearing caps before starting any measurements. You may have some cam bearing caps that were not tightened properly or that loosened up on you. The reason I bring this up is that, for normal wearing, the valve clearnace usually gets tighter, not looser. The valve seal edges usually wear faster than the shims in contact with the cams. So if anything, with normal wear, the valve train noise tends to diminish with age. A new ticking noise could be more of a problem that resulted from the headgasket replacement process, as the cams needed to be removed to get the head bolts out. So a new ticking noise could be from cam bearing caps not being torqued properly or just plain not tightened at all.

[5sfeCelica]

Originally Posted by 93celicaconv

Sounds like you didn't take the head apart to put in new valve seals, and to machine the headgasket surface so it was perfectly flat before reinstalling the head? I would have recommended you do that, especially the machining work, because if the head's mating surface to the headgasket isn't nearly perfectly flat, you will likely have headgasket problems surfacing again in the future.

There is a complete service manual for 5th Gen Celicas on www.celicatech.com. I would recommend you go to that forum, get to the 5th Gen Celica service manual, and go to pages EM-22 to EM-25. It will show you exactly how to measure valve clearance and how to calculate the new, replacement shims you need to order to get your clearances back within spec.

Did the valve train ticking just start happening after the headgasket change? If so, I would check the torque on all the cam bearing caps before starting any measurements. You may have some cam bearing caps that were not tightened properly or that loosened up on you. The reason I bring this up is that, for normal wearing, the valve clearnace usually gets tighter, not looser. The valve seal edges usually wear faster than the shims in contact with the cams. So if anything, with normal wear, the valve train noise tends to diminish with age. A new ticking noise could be more of a problem that resulted from the headgasket replacement process, as the cams needed to be removed to get the head bolts out. So a new ticking noise could be from cam bearing caps not being torqued properly or just plain not tightened at all.

Thanks for the info and i did get the head machined and new valve seals and guides so adjusting the valves would be mandatory after head work has been done

[93celicaconv]

Originally Posted by 5sfeCelica

Thanks for the info and i did get the head machined and new valve seals and guides so adjusting the valves would be mandatory after head work has been done

No, that's not true at all. Did you do the work, or did a mechanic do the work on the head?

When you replace the valve seals, all you are doing is removing the valve components, pulling the old seal out, installing the new seal, then putting all the components back in. Done properly, the valve face and head are marked so the valve is put back in the same orientation. When put back together, yes, valve lash should be checked to make sure it is within specs. Most times, because the valves themselves are not lapped or the seats are not ground, the lash will be within spec.

Now, it may be possible, given you had new valve seals put in, that the shim for each valve wasn't put back for each valve from where they came. And if valve lash wasn't checked on the end, that could cause your new ticking sound. That means one valve has a thinner shim now than it orignally had and has too much lash, so it is ticking. Worse, another valve has a thicker shim that it originally had, has no valve lash (so it runs silent), but it doesn't close and seal properly, so a lost of compression is possible and this valve won't cool properly, so it could become burnt soon.

I had this happen to one of my heads coming out of a shop after machining the head gasket surface and putting new valve seals in - the ticking sound. I check the valve lash, and one was too loose and one was too tight. Took it back to the mechanic, and sure enough, he accidentally switched 2 shims between two valves, and never checked the final valve lash upon reassembly. After the swap, lash readings were all good, and compression valves were good, so I didn't damage a valve because of this. Just something to be aware of.

[5sfeCelica]

Originally Posted by 93celicaconv

No, that's not true at all. Did you do the work, or did a mechanic do the work on the head?

When you replace the valve seals, all you are doing is removing the valve components, pulling the old seal out, installing the new seal, then putting all the components back in. Done properly, the valve face and head are marked so the valve is put back in the same orientation. When put back together, yes, valve lash should be checked to make sure it is within specs. Most times, because the valves themselves are not lapped or the seats are not ground, the lash will be within spec.

Now, it may be possible, given you had new valve seals put in, that the shim for each valve wasn't put back for each valve from where they came. And if valve lash wasn't checked on the end, that could cause your new ticking sound. That means one valve has a thinner shim now than it orignally had and has too much lash, so it is ticking. Worse, another valve has a thicker shim that it originally had, has no valve lash (so it runs silent), but it doesn't close and seal properly, so a lost of compression is possible and this valve won't cool properly, so it could become burnt soon.

I had this happen to one of my heads coming out of a shop after machining the head gasket surface and putting new valve seals in - the ticking sound. I check the valve lash, and one was too loose and one was too tight. Took it back to the mechanic, and sure enough, he accidentally switched 2 shims between two valves, and never checked the final valve lash upon reassembly. After the swap, lash readings were all good, and compression valves were good, so I didn't damage a valve because of this. Just something to be aware of.

I had a machine shop do the work to the head and i think they might have mixed up the shims and i havent had the car running for long periods of time since i did hear the ticking i didnt want to damage anything else thanks for your time and info

[5sfeCelica]

Well i measured everything out and i had a few that were off and now im trying to figure out which new shims i need by this selection chart i found online and it is showing that the shim thickness is .0984 for the smallest size and it doesnt make any sense to me i measured the thickness of my old shim then i subtracted the clearence measured to the required measurement and added it to the thickness of the old shim and none are anywhere near that thick any ideas on what im doing wrong?

[93celicaconv]

It would be best if you could give me a real example of a clearance you are measuring, and which valve it is (an exhaust or an intake valve).

The formulas are quite simple for a 5S-FE:

Intake: N = T + (A - 0.009 in.)
Exhaust: N = T + (A - 0.013 in.)

where;

N........thickness of new shim
T........thickness of used or old shim
A........measured valve clearance

The shim you end up selecting is one with a thickness as close as possible to the calculated value.

[5sfeCelica]

Originally Posted by 93celicaconv

It would be best if you could give me a real example of a clearance you are measuring, and which valve it is (an exhaust or an intake valve).

The formulas are quite simple for a 5S-FE:

Intake: N = T + (A - 0.009 in.)
Exhaust: N = T + (A - 0.013 in.)

where;

N........thickness of new shim
T........thickness of used or old shim
A........measured valve clearance

The shim you end up selecting is one with a thickness as close as possible to the calculated value.

Thanks for the formula, the other problem i just ran into is for example one of the new shims i need is .234 and on the shim selecting chart the thinest one is .0984 am i doing something wrong?

[93celicaconv]

Originally Posted by 5sfeCelica

Thanks for the formula, the other problem i just ran into is for example one of the new shims i need is .234 and on the shim selecting chart the thinest one is .0984 am i doing something wrong?

Please list the measured values of N, T & A (and the units these measurements are in, like inches, millimeters, etc.).

[5sfeCelica]

Originally Posted by 93celicaconv

Please list the measured values of N, T & A (and the units these measurements are in, like inches, millimeters, etc.).

Intake side
N= .117(.015-.009) thats in inches so the new shim would have to be .123(inches)

The chart I was talking about is off of this website

http://arrc.epnet.com/autoapp/8955/8...ADJUSTMEN1.htm

[93celicaconv]

OK, forget N. Please provide me with the measurements (in inches) for T & A. N is what we are looking to calculate. T & A you are able to measure from what you have. Please provide those measurements.

[5sfeCelica]

Originally Posted by 93celicaconv

OK, forget N. Please provide me with the measurements (in inches) for T & A. N is what we are looking to calculate. T & A you are able to measure from what you have. Please provide those measurements.

Ok, This is for an Intake side

T=.117(inches)
A=.015(inches)

[93celicaconv]

OK, an intake valve has a shim that you measured as 0.117", and you measured a valve clearance of 0.015". Ideal valve clearance is 0.009". Using the formual for an intake valve:

N = T + (A - 0.009 in.)

N = 0.117" + (0.015" - 0.009")
N = 0.117" + (0.006")
N = 0.123"

Your ideal new shim thickness should be 0.123", according to your measurements. Shim #13 is 0.122". Shim #14 is 0.124". You are right in between. Typically, valve clearance gets tighter with age, so you will want to error on the loose, or greater valve clearance side when you cannot get the perfect shim thickness. As such, your choice for this valve should be Shim #13 (0.122"), which will result in a valve clearance of 0.010".

Now you can see how the math is done. So you just need to do the same for all the rest of the intake valves. Then use the other formula, but the same methold of calculating, for the exhaust valves.

Hint: You may find some valve clearances too small, and others too large. You will want to determine if, in these cases, you can find the shims that were put in the wrong valves. Perhaps you don't need to buy any at all, you just need to get the right shims on the right valves again. I think your chances are high this is what you will find.