2s-e valve problem after rebuild - Toyota Nation Forum : Toyota Car and Truck Forums

ski2xs · 08-21-2008, 07:43 PM

Here is a weird problem that someone here might have seen before.

Rebuilt a 2s-e completely to include new valve job and new lifters. I primed the lifters as recommended. Engine started and ran, but wouldn't fire at low rpm on #2. Compression check showed low compression and seemed to show cross compression between #1 and #2.

I didn't exactly like the head gasket supplied with the rebuild kit anyway so I pulled the heads back off to check everything, gasket looked like it sealed fine. I reinstalled with a felpro, got it all back together and now more problems. Seems now that the valves aren't closing all the way. I had originally thought that the cam dowel might have sheared for some reason and that the cam timing was off around -30 to -40 degrees. I checked that and it's fine.

I can only assume bad aftermarket lifters that are pumping up too much, or the machine shop left the valve stems too long after the rebuild.

Any other thoughts out there??

Also, does anyone have the valve timing specs on this engine. I found the 22r specs online but can't find the 2s-e. I'd assume it would be in the neighborhood of -9 BTDC at opening to around 40 ABDC to close for the intake.

Anyone ever ran across something like this before???

ski2xs · 08-21-2008, 07:48 PM

BTW, this is a problem that is now affecting more than one cylinder. I pulled the cam back off, bled the lifters down just a bit, reinstalled and it ran okay for awhile . . .I guess until the lifters pumped back up fully.

Another thought. . . .weak springs??? Oil press too high??? I would have assumed (we know what that means) that the machine shop checked the spring tension as well as the installed spring height. . . I don't have a mechanical oil press tester so I can't check that right now.

fredk · 08-21-2008, 07:59 PM

bleed em off again, and do a compression test, then let it run till it runs bad and do another one

ski2xs · 08-21-2008, 08:15 PM

Right der wit cha on that Fred. But I like the way you think!!

Already did the compression check just after I had bled the lifters down before I fired it off. Came up with app. 135 across the board. (also, the leak-down with the cam not installed so that all valves are closed is good too) Now I'm getting app. 60 on #1 (haven't checked all four yet because I pretty much know what I'll find. . .however I'll do that right now just for S&G's)

Another thing I want to try and find is the specs on the installed valve STEM height. I know that after grinding the valves in that the installed stem height will be a bit more. Again . . .something I ASSUMED the machine shop would take care of. After speaking with him about it I'm beginning to wonder.

Thanks for the thought on that.

ski2xs · 08-21-2008, 08:23 PM

Oh . . .and one MORE thing. . . I quess I could just. . re engineer it. . and pull the heads again, attach the cam, set the rotation to the exact angle when the valves should close. . .Then measure the amount that they're still open and trim that much off each respective valve stem.

I don't want to be doing this though and find out that the real problem was something like the aftermarket lifters being out of spec or the springs being weak.

ski2xs · 08-22-2008, 11:02 PM

Yup, I'm thinking more and more valve stem height. Haven't set up a jig to check each one individually yet, but a straight edge across all of them reveals that the machinist didn't even normalize them. . . one of the exhaust valves in particular is app. .020 shorter than the rest. . .others are coming in different too. I'm wondering if I should just normalize all exhausts valves to the shortest of the exhaust group and do the same with the intakes. . .

.020 is the spec wear limit though!

JMSports · 08-24-2008, 09:44 PM

Dump a tiny bit of oil in the cylinder with the lower compression. Run the engine till its warm, then turn it off and re-test the compression in all 4 cylinders. If the compression is up to normal right after doing this, it says that the cylinder is leaking pressure somewhere in the engine due to a bad seal, gasket, or mistiming of the cylinder.

I know cause we fixed my brothers 4 Cylinder XJ1200 Legends Car race motor this way. (low compression between 2 and 3 i believe it was)

EDIT: Also if you retest the compression a few times and the low compression cylinder switches to another cylinder (like the first time it may be #2 with low comp. and the second time its #1 with low comp.) then you know between which cylinders the pressure leak may be.

Doctor J · 08-25-2008, 10:23 AM

The cam of 2S engine has press-on lobes, that can become loose [according to the AERA] this causes uneven compression and rough running.
I have never personally seen the car with this problem, [but I am not engine machinist] but I think it can be good idea to inspect the cam.

ski2xs · 08-25-2008, 12:59 PM

JM,

It's definitely a valve lift problem, read lower.

Dr. J,

I was wondering about the lobes being press on. . . I didn't know of the problem though. . . however they don't feel loose by hand.

I've pulled the heads again, primed the lifters and installed the cam. . .There is with 100% certainty a valve lift problem. . .on #1 firing I can both the exhaust and intake are still slightly open. . . .

Strange thing is that I primed and installed one of the old lifters on intake #4 and it doesn't display this problem. Now, the stems, as I noted earlier, were not normalized by the machine shop so I'm taking the entire assembly back to them along with four of the old lifters (I had purchased the new ones from them too) to let them figure it out. . . . bad aftermarket lifters?? Valve stem height?? or a combination of both.

I'll post the results once I know.

Thanks for the responses!!

fredk · 08-25-2008, 02:15 PM

are the valves the ones that were in the head or did you buy some new ones?

ski2xs · 08-25-2008, 05:59 PM

Fred,

Only one valve was new (#3 exhaust) . . .like I said, the machinist didn't even normalize the stem heights as when I placed a straight edge across the stems the new valve was almost .020 lower. . .none however were the same although the variation was less and in a range of .004 - .008. Unfortunately I didn't have the time to check and see if this valve was closing completely with the new lifters and I have still been unable to locate the valve timing specs in order to set the cam in position for proper checking.

I'm still pretty sure that the problem is most likely a combination of both valve stem height and poorly manufactured aftermarket lifters. It would have been nice if I had found the timing specs and was able to check the new valve in relation to the older ones seeing as it set much lower!!

Again, if anyone can come across these specs (especially if someone can come across anything in re: to a valve stem installed height) please let me know. I've scoured the net and have found nothing besides info on 22r's and other common engines from the aftermarket cam site.

Thanks Fred, have a great day.

fredk · 08-25-2008, 06:10 PM

now the head is off turn it over on the combustion chamber side and see if the valves are pretty much level or sticking up and look for any valve head down pretty low

ski2xs · 09-04-2008, 04:47 PM

UPDATE!

Well, had the machine shop normalize all the stem heights to the lowest one in the group. Got it back, primed the new lifters and installed the cam (with heads off the engine). Checked each cylinder group and all valves were still hanging open app. .030.

HAS to be the aftermarket lifters. . . .disassembled, cleaned and checked the old lifters . . .Primed them and installed them. . . .no valves hanging open!!!

Machine shop is now going to get two different sets of lifters (one set from the same aftermarket and one set from a different vendor). I'm going to take the heads, cam, lifters that are giving problems and the original lifters. We'll narrow this damn thing down. Once I have verified my theory 100% I'll provide the manufacture name of the aftermarket lifters that have given me such grief so all that read this won't ever have to go through what I have!!

Thanks all!

fredk · 09-07-2008, 08:49 PM

:hypnosis:

ski2xs · 10-18-2008, 10:50 PM

Okay all,

Back on this after taking some time off. Both my machine shop guy and I thought we had it figured out, obviously not.

No set of lifters has effectively cured this problem, neither the old ones or any of the other manufacturer new ones. I was mistaken that the old ones were working right. ANYway, same thing, valves not seating fully at TDC firing position. After normalizing the installed stem height and taking them down to minimum length #1 does 'okay' with 120psi, but no compression on #2 and very weak on #3 and #4.

I've figured this much out now. I can rotate the engine by hand and bring each piston (particularly #2) up to firing position. The valves will still be partially open and I'll get leakdown past them. If I allow the engine to sit in this position for app. 10 - 15 minutes the valves will seat and seal at which time I get normal leakdown results. I can then rotate it again one full firing revolution (720 crank degrees) back to the same pistons firing position and end up with the same results. . i.e. valves won't seat until it sits for app. 10 - 15 mins.

BTW, as mention earlier in the thread I've also installed the lifters only partially primed. When I did this I got decent (and consistent across all cylinders) compression and the valves would seat fully. However, after installing the plugs and running it enough to allow the lifters to prime up by the engine oil pressure, I end up with the same problem again.

Weak springs??

Again, something I would think the damn machine shop would check. SOOOooo, I'm pulling the damn cam tower again in the next few days at which time I'll check damn installed spring heights once more. I'll order some damn shims as necessary to correct any damn problems there. I'm going to pull the damn springs on #2 (with head installed!!!, yup, I know how to do this!) and check the damn tension on those to see if they're weak. . . . damn!

It's about the only thing left that I can even begin to imagine would cause this. I've never ran into a weak spring problem in my life and have always thought they only manifested themselves in high RPM floating. As usual, any other suggestions are more than welcome.

If this hadn't turned into a personal challenge thing, I'd of plugged this freakin' thing with a .308 FMJ already.

Thanks guys!