Why are the Tercel valves adjusted hot?

[Jooseppi Luna]

EDIT - from ARCHINSTL: I did not take your response as arrogant. I tend to write in a now-archaic style (perhaps because I am antediluvian?).[/quote]

You win. I had to use Google to fully grasp your post .

[JesseN]

Hey man I didn't take anything you said as whining. I hate burning my hands too. The thing that is nice is that the aluminum valve cover cools pretty quickly in relation to the head. It is thinner and if you just wait about 3 mins after warm up the cover should be cool enough to handle.

A tip on the valve cover replacement. If the gasket is not new you need to replace it when you do the valve adjustment. These gaskets get hard and brittle over time from heat and can crack or just not seal anymore. Make sure to replace the rubber half moon seals at the front and back of the head too. You can buy a valve cover gasket kit with or without the half moons. Use a tiny amount of sealer (I like Hi-Tack) to hold the half moons in place while installing cover. Also a little bit of silicone between the the valve cover seal and the half moons has always helped keep a good seal on my Toyotas.

These covers only have 3 nuts holding them down and from the factory they are assembled using a three socket machine that tightens and torques the cover down all at the same time. Since you can't do this tighten the cover nuts down evenly and slowly to the proper torque spec. These cover are a notrious problem child for leaking. Improper torque on anyone of the three nuts can cause a leak that is a pain to stop sometimes. You can also have a friend help and one of you can tighten two nuts and the other can tighten one all at the same time so the evenness of tightening can be as close as possible. Just dont overtighten...some think that when it is so tight it won't tighten anymore that it is good, this is usually when a problem starts. Seals can get pinched, pushed out, or cut from overtightening.

Good luck on the project...it ia basic one but the other tips are nice to know too. I suggest adjusting the valves and then rechecking them a day later to see if there is any clatter that may still need to be adjusted out. A little noise is common on these cars but too much means the clearances are too far off and the car might not be running to its fullest potential.

Peace

Thank you for the great sidebar of info! I just got my 86 Wagon (2WD) and I think she is in desperate need of an adjustment because sometimes when accelerating it sounds like someone playing drums with 20 tin spoons. When I do the warm up should I bring the temp to normal operating or just a trip to the store and back? Aside from paying attention to the pattern and torque spec is there anything else that I should consider being extra delicate with while I am there? Anything I may lose? Would an assistant be needed or should my two hands be alright for this job? Do the plugs need to be removed? I may as well replace them anyway right?

Thank you,

Jesse

[dlb]

welcome, jessen. warm the car up fully and then pop the hood. let the engine cool until you can touch it without hurting yourself, then take the valve cover off to adjust the valves. it's easy to do so no assistant is necessary.

no need to remove the plugs when adjusting the valves. no need to replace them unless the electrode is visibly worn or melted, or you don't know when they were changed last and there's a good chance it was aeons ago.

[Petros]

Some brands of spark plugs break down internally, and even though the electrodes look okay, they may be grounding internally intermittently, delivering poor fuel economy and power output. I have found the factory type NGK spark plugs hold up very well and I can keep driving them as long as my fuel economy is good (I check it most fill-ups so I know it is running good). I have also tried the more expensive plugs with the small electrods but I found those do not hold up as well as the standard plug, so that is what I buy.

The last time I used Champion spark plugs I could never go between tune ups with one or more of the spark plugs breaking down and needed to be replaced. That was many years ago, but I have not purchased Champion spark plugs since (I notice the same problem in my lawn mower, chain saws and other yard equipment with the Champion spark plugs, so I buy Autolite for those).

[JesseN]

Thank you very much for all the help. Everyone! This forum has a great group of people on it. Last and final stupid question. How do I rotate the engine when I am adjusting the valves? Do I try to start it or am I using a wrench somewhere to apply force and turn? If so, what kind of wrench and where?

[dlb]

to rotate the engine, just grab the lowest, biggest pulley at the front of the engine. this is the crank pulley. with the spark plugs out, you should be able to turn it with medium effort.

*edit* petros' post below reminded me to note that the trans should be in neutral.

[Petros]

I found the easiest way to rotate the engine is to put in gear, my preferance is reverse, and than push the car backwards watching the crank pulley. when at top dead center you can adjust both valves on the number one cylinder, and the forward valve on the number two and three. Number four cylinder the valves are "teetering" half way between intake and exhaust stroke and because of the valve timing overlap you can not do either. than I push the car backwards watching the front pulley (when in reverse the engine will rotate in the correct direction when you push the car backwards which is easiest when standing in the front). When the front pulley makes one rev and comes back up to TDC it puts the number four cylinder at TDC, so you can adjust both valves on the number four cylinder, and than the rear most valve on cylinders number two and three. You can tell by wiggling them up and down, if there is no gap to wiggle, than they are being lifted by the camshaft. Inspecting the cam shaft will also tell you if the rocker arm is down on the base circle of the cam or on the cam ramps going up or down.

some people like putting each cylinder in turn at TDC, but I have not found this to be necessary.

[JesseN]

Hey everyone need your expert advice again. Today I attempted the valve adjustment. Everything seemed to go fine, I went for a decent drive. Removed the plugs and rotated to TDC and 0. Cyl 1 intake and exhaust were loose and 4 was tight just like the FSM said. I adjusted cyl 1 intake and that seemed to go fine but when I started to back out the adjustment screw on the exhaust it started to push up as i backed out and I couldnt get the feeler gauge in there. So then after backing out a bit more suddenly there allot of gap and so I start to tighten down and check for drag. What am I doing wrong? Is the rocker arm supposed to rock a little bit and I am to push and hold it down on the feeler gauge and then tighten and drag? Im confused. I did this on my Accord with no problem but I guess I am in over my head here. Started after I made my misadjustment and Its really noisy and smells really rich. Has more power though? Sorry for asking so much but how much should I be having to back the adjustment screws out before there is enough space to even put the feeler gauge in? Guess l have to adjust cold, rats! Thanks for your help.

Worried, Jesse

[dlb]

Is the rocker arm supposed to rock a little bit and I am to push and hold it down on the feeler gauge and then tighten and drag?

yes, there should be some gap between the rocker arm and valve stems.

I adjusted cyl 1 intake and that seemed to go fine but when I started to back out the adjustment screw on the exhaust it started to push up as i backed out and I couldnt get the feeler gauge in there.

how many valves did you find to have no gap at all? are you sure you were checking the correct exhaust valves? according to the FSM, you must adjust the intake valves for the 1st and 2nd cylinders, and exhaust valves for the 1st and 3rd cylinders. i would double check the diagram and make sure you are adjusting the valves in the correct order.

don't worry though, these are non-interference engines so you're not going to mess anything up. just keep at it and you'll get it sorted out.

[JesseN]

Thank you. I followed the manual and it said to adjust the valves you mentioned first and then do one full rotation and work on the others. I guess what I am really confused about is how much play there should be. Like you can rock the rocker arm towards the back curved piece and hold it there and that created like half inch gap so am I to turn the adjustment screw all the way until the gap is gone and the arm will not rock at all minus the feeler measurement? Or am i supposed to not worry about the free play and hold it closed and adjust it? Is there anyway I can call you or you call me? Please. I will paypal you a few bucks for your time. I have to drive this puppy to work tomorrow.

[rer233]

Years ago, an old brit friend of mine told me the easiest way to remember the order to adjust valves on ANY inline 2 valve/cylinder engine is to take the # of cylinders, multiply by 2, and add 1. On our 4cyl tercels, you come up with 9. So to adjust the first valve (closest to the radiator) turn the engine till the eighth valve (9 minus 1) is fully open and now set the lash on the first valve. For the second valve back, turn the engine till the seventh valve is fully open and adjust the second and so on. Irealize that this method is a whole lot more time-consuming, but it seems you're hopelessly lost, and this method works on any engine- regardless of firing order, valve overlap, etc.

Good luck!

[JesseN]

Years ago, an old brit friend of mine told me the easiest way to remember the order to adjust valves on ANY inline 2 valve/cylinder engine is to take the # of cylinders, multiply by 2, and add 1. On our 4cyl tercels, you come up with 9. So to adjust the first valve (closest to the radiator) turn the engine till the eighth valve (9 minus 1) is fully open and now set the lash on the first valve. For the second valve back, turn the engine till the seventh valve is fully open and adjust the second and so on. Irealize that this method is a whole lot more time-consuming, but it seems you're hopelessly lost, and this method works on any engine- regardless of firing order, valve overlap, etc.

Good luck!

Thank you! This worked like a charm. So my problem was that when following the FSM and setting to TDC and 0 Cyl one Intake wasn't anywhere near the heel but a little ways from toe. Not sure why that is but followed your advice and all went perfect she is running better than ever. Still needs a hot adjustment but I couldn't be happier, you saved me. And that goes for all of you! If anyone is ever in Oregon let me buy you a beer.

Jesse

[dlb]

good for you, jesse. FYI, i have only adjusted the valves on a terc once and i did them cold. the car still runs great so i haven't bothered doing the hot adjustment. i'm not sure why the FSM has the specs for both hot and cold adjustments but the cold ones worked fine for me.

[JesseN]

I am going to do the hot adjustments tonight. I am thinking all should go well now. What is the torque spec for the valve cover? I have just been tightening it down not too tight but I didn't know if there is an official spec somewhere? I could not find it in the FSM.

Thank you,

Jesse