quote:

Originally posted by HRK:
Call around junk yards see if you can find a used engine from any toyota that uses that same block, swap it out trade the old in for core if they want.

or, drive it, it's just a little off idle stumble, live with it and don't throw any more green at it until it pukes, park it, walk away...

quote:

Originally posted by egregore:
Leakage out of the exhaust valve? There might still be a small chance, if not of saving it, buying it some more time. The valve cover has to come off to check it, but this engine has a "shim over bucket" valve adjustment, not self-adjusting hydraulic lifters. If the valve clearance has closed up, the exhaust valve will be held off its seat a little bit and you will lose compression. However, not only is shim valve adjustment a PITA, decreased valve clearance can only be caused by the valve receding into the head. So there is not only that problem, but if this has gone on long enough, the valve would be burnt anyway. But seeing if the clearance is too tight could still be useful from a diagnostic standpoint.

quote:

Originally posted by Shifferbrains:

quote:

Originally posted by egregore:
Leakage out of the exhaust valve? There might still be a small chance, if not of saving it, buying it some more time. The valve cover has to come off to check it, but this engine has a "shim over bucket" valve adjustment, not self-adjusting hydraulic lifters. If the valve clearance has closed up, the exhaust valve will be held off its seat a little bit and you will lose compression. However, not only is shim valve adjustment a PITA, decreased valve clearance can only be caused by the valve receding into the head. So there is not only that problem, but if this has gone on long enough, the valve would be burnt anyway. But seeing if the clearance is too tight could still be useful from a diagnostic standpoint.

If this were my vehicle, this is exactly what I would do. If the valves are indeed tight and can be brought back into specifications, it might be worth doing this. Won't be so costly, and the engine can be run for many more miles.

quote:

Originally posted by thumperfbc:

quote:

Originally posted by Shifferbrains:

quote:

Originally posted by egregore:
Leakage out of the exhaust valve? There might still be a small chance, if not of saving it, buying it some more time. The valve cover has to come off to check it, but this engine has a "shim over bucket" valve adjustment, not self-adjusting hydraulic lifters. If the valve clearance has closed up, the exhaust valve will be held off its seat a little bit and you will lose compression. However, not only is shim valve adjustment a PITA, decreased valve clearance can only be caused by the valve receding into the head. So there is not only that problem, but if this has gone on long enough, the valve would be burnt anyway. But seeing if the clearance is too tight could still be useful from a diagnostic standpoint.

If this were my vehicle, this is exactly what I would do. If the valves are indeed tight and can be brought back into specifications, it might be worth doing this. Won't be so costly, and the engine can be run for many more miles.

So this is done with the head in place but valve cover off? Does the cam have to come off? My buddy who has been helping me is a former GM tech so some of this Toyota stuff is new to him. I remember he mentioned that he isn’t a fan of the shin system used on Toyota’s but he was willing to replace the stem seals. Maybe this is in his skill range. Any idea how many hours it is to complete? My “regular” mechanic didn’t mention it as an option.

quote:

Originally posted by Shifferbrains:

quote:

Originally posted by thumperfbc:

quote:

Originally posted by Shifferbrains:

quote:

Originally posted by egregore:
Leakage out of the exhaust valve? There might still be a small chance, if not of saving it, buying it some more time. The valve cover has to come off to check it, but this engine has a "shim over bucket" valve adjustment, not self-adjusting hydraulic lifters. If the valve clearance has closed up, the exhaust valve will be held off its seat a little bit and you will lose compression. However, not only is shim valve adjustment a PITA, decreased valve clearance can only be caused by the valve receding into the head. So there is not only that problem, but if this has gone on long enough, the valve would be burnt anyway. But seeing if the clearance is too tight could still be useful from a diagnostic standpoint.

If this were my vehicle, this is exactly what I would do. If the valves are indeed tight and can be brought back into specifications, it might be worth doing this. Won't be so costly, and the engine can be run for many more miles.

So this is done with the head in place but valve cover off? Does the cam have to come off? My buddy who has been helping me is a former GM tech so some of this Toyota stuff is new to him. I remember he mentioned that he isn’t a fan of the shin system used on Toyota’s but he was willing to replace the stem seals. Maybe this is in his skill range. Any idea how many hours it is to complete? My “regular” mechanic didn’t mention it as an option.

If he is going to do the stem seals, he has to remove the cams, buckets and shims. Before doing all that, have him measure the valve clearances. Most times you can replace the shims on a 'shim over bucket' without removing the cams.

Do you get a nice puff of blue smoke when the engine is cold started? does the engine use an excessive amount of oil between changes? If not, a valve adjustment may take care of the missing on cylinder 3 and may not really need to replace the guide seals. That is if the clearances are tight. If the clearances are ok, then the heads will have to be removed to do a valve job.

This is where you have to look at the alternatives, the cost of a valve job, the cost of the junk yard engine, or getting rid of the vehicle.

You can just drive it like you said, but the piper will have to be paid when it comes time for the smog inspection. Also, be aware that you are potentially damaging the catalytic converter by running the engine with the misfire.

quote:

Originally posted by thumperfbc:

quote:

Originally posted by Shifferbrains:

quote:

Originally posted by thumperfbc:

quote:

Originally posted by Shifferbrains:

quote:

Originally posted by egregore:
Leakage out of the exhaust valve? There might still be a small chance, if not of saving it, buying it some more time. The valve cover has to come off to check it, but this engine has a "shim over bucket" valve adjustment, not self-adjusting hydraulic lifters. If the valve clearance has closed up, the exhaust valve will be held off its seat a little bit and you will lose compression. However, not only is shim valve adjustment a PITA, decreased valve clearance can only be caused by the valve receding into the head. So there is not only that problem, but if this has gone on long enough, the valve would be burnt anyway. But seeing if the clearance is too tight could still be useful from a diagnostic standpoint.

If this were my vehicle, this is exactly what I would do. If the valves are indeed tight and can be brought back into specifications, it might be worth doing this. Won't be so costly, and the engine can be run for many more miles.

So this is done with the head in place but valve cover off? Does the cam have to come off? My buddy who has been helping me is a former GM tech so some of this Toyota stuff is new to him. I remember he mentioned that he isn’t a fan of the shin system used on Toyota’s but he was willing to replace the stem seals. Maybe this is in his skill range. Any idea how many hours it is to complete? My “regular” mechanic didn’t mention it as an option.

If he is going to do the stem seals, he has to remove the cams, buckets and shims. Before doing all that, have him measure the valve clearances. Most times you can replace the shims on a 'shim over bucket' without removing the cams.

Do you get a nice puff of blue smoke when the engine is cold started? does the engine use an excessive amount of oil between changes? If not, a valve adjustment may take care of the missing on cylinder 3 and may not really need to replace the guide seals. That is if the clearances are tight. If the clearances are ok, then the heads will have to be removed to do a valve job.

This is where you have to look at the alternatives, the cost of a valve job, the cost of the junk yard engine, or getting rid of the vehicle.

You can just drive it like you said, but the piper will have to be paid when it comes time for the smog inspection. Also, be aware that you are potentially damaging the catalytic converter by running the engine with the misfire.

I sent him the text by egregore a few minutes ago and he says it makes sense but he’s never done it and doesn’t know how.

Do you still do side jobs?

quote:

Originally posted by Shifferbrains:
Mike, I sent you the valve adjustment procedure to your listed email. This is from Alldata, and should be a huge help to your friend.

quote:

Originally posted by thumperfbc:

quote:

Originally posted by Shifferbrains:
Mike, I sent you the valve adjustment procedure to your listed email. This is from Alldata, and should be a huge help to your friend.

Thanks!

I’m surprised they are selling crown Vic’s. We’ve given up on the other options and are sending the CV’s down south for refurbishment.

quote:

Originally posted by thumperfbc:
My buddy is perusing the Alldata. Thanks again for that.

From what I understand you are saying is the valve may be misadjusted resulting in the valve not closing all the way which would result in the loss of compression revealed by the leakdown. I get that.

But it doesn’t explain oil in the combustion chamber. If we assume the rings are intact, as the mechanic believes, then we have oil leaking through the valve seals or the valve guides are worn to the point that the seal can’t seal. Correct?

So we are looking at potentially multiple issues.

quote:

Originally posted by Shifferbrains:

What I'm saying based on the evidence we have right now(no blue smoke on cold start-up, and no major signs of oil consumption) is that the oil present is not the cause of the misfire, but the valves not fully seating is. If the valves can be corrected by a valve adjustment, the presence of oil may be a non-issue considering the age of the engine.

As was brought up before, the oil may be coming from the PCV system and not the seals. Usually there will be multiple cylinders with leaking seals as they will tend to degrade at the same rate. Of course, if the valve guide on this cylinder is worn more than the others, this can explain the oil present.

Bottom line, if the valves are indeed tight and can be corrected, it may not be worth the extra expense and time to change the seals if there isn't real evidence that the engine is burning oil. Especially with the mileage on this engine. The evidence is pointing to the valves causing the misfire, not oil fouling.

quote:

Originally posted by thumperfbc:

quote:

Originally posted by Shifferbrains:

What I'm saying based on the evidence we have right now(no blue smoke on cold start-up, and no major signs of oil consumption) is that the oil present is not the cause of the misfire, but the valves not fully seating is. If the valves can be corrected by a valve adjustment, the presence of oil may be a non-issue considering the age of the engine.

As was brought up before, the oil may be coming from the PCV system and not the seals. Usually there will be multiple cylinders with leaking seals as they will tend to degrade at the same rate. Of course, if the valve guide on this cylinder is worn more than the others, this can explain the oil present.

Bottom line, if the valves are indeed tight and can be corrected, it may not be worth the extra expense and time to change the seals if there isn't real evidence that the engine is burning oil. Especially with the mileage on this engine. The evidence is pointing to the valves causing the misfire, not oil fouling.

Ok, thanks for the clarification. Essentially you are suggesting that the clearance be measure (feeler gauge?) and any found out of spec should be rectified. This is done by changing shins that appear to sit on top of some sort of cover on the valve spring and is directly pressed on by the cam.

Right?

If my buddy was willing to do the seals, I can talk him into this I think. While in no expert, this doesn’t seem to be as big of a job. Seals requires the cams and the “bucket” and springs getbremoved while these adjustments can be done with the cam intact.


Am I getting it?

quote:

Originally posted by thumperfbc:
The A/C has been acting up since the leakdown test was done. Is there something that he may have forgotten to put back together following the test? Sometimes it works great as it had, sometimes the air is not cold at all, particularly at idle.

quote:

Originally posted by Shifferbrains:

quote:

Originally posted by thumperfbc:
The A/C has been acting up since the leakdown test was done. Is there something that he may have forgotten to put back together following the test? Sometimes it works great as it had, sometimes the air is not cold at all, particularly at idle.

Check to make sure the radiator cooling fans are on when the A/C is on and at idle.