TB/Oil seals question

[majones]

I have a 94 Camry it has the 5-SFE 4 cyl with ~210K miles. I lost the water pump recently and had some oil pre-existing oil leaks from the timing belt area.

I am part way through a timing belt, water pump, oil seals change following a couple of the DIY guides on this site--thanks guys it's been a great help. Anyway at this point basically everything is out/disassembled. I was planning to replace the cam and outer crank oil seals as well as the oil pump shaft seal and o-ring as well as the timing belt and water-pump assembly and its seals and the tensioner spring.

A couple of things I'm unsure of is the gasket between the back-half of the oil pump and the engine block--is this one worth changing or not normally an issue? Also from the manual it looks like there is a rear crankshaft seal--again worth it or a non-issue? Finally tensioner and idler pulley's...mine seem to spin fine, is it generally advisable to change these with the TB replacement. Any other low dollar high-impact things I should consider doing while I'm in here?

Thanks for your advice!

[new echo owner]

If you want to replace the oil pump cover to block gasket, you will need to remove the oil pan, since the oil pickup screen is bolted onto the cover from below. To replace the rear main seal, either the engine or the transmission will need to be removed to gain access. But if they are leaking, might as well do it now.

As far as the tensioner and the idler, with 210K on them, it would be a good idea to replace them. Seems like you have everything well covered there, the only item I would add is the thermostat, since you are replacing the water pump already; the coolant will be drained, and just two more nuts to replace the thermostat.

N.E.O.

[majones]

Thanks for the advice N.E.O. Think I'll go for the new pulleys,thermostat and attempt the oil pump to block gasket. I was confused on the location of the rear crankshaft seal it may be a job for a warmer day.

[new echo owner]

Keep us posted on your progress! Take some pictures and post them if you can, pretty sure others would like to see how things look.

N.E.O.

[majones]

Just an update on my repair and current issues. Sorry for the long note but I would appreciate any advice.

I put things back together last night. I replaced the cam/crank seals, both idler pulleys, water pump, thermostat and the shaft seal and o-ring in the oil pump as well as the timing belt. I passed on the oil pump to block seal, I wasn't sure it was leaking. I also pulled the distributor and replaced the o-ring.

I believe the timing belt alignment went ok, but... I followed the manual supplemented with one of the DIY threads on the subject here. The TDC setting went ok, i think, the marks lined up and I rotated thru 720 deg twice to double check. The 0 mark on my TB cover is damaged but I can see the zero and guesstimated that the mark would be in-line with it. There was something in the manual about:

(d) w/ Green Tension Spring:
Slowly turn the crankshaft pulley 1 and 7/8 revolu–
tions, and align its groove with the mark at 45

BTDC
(for No.1 cylinder) of the No.1 timing belt cover.

NOTICE: Always turn the crankshaft clockwise.

I didn't do this, wasn't sure if this was for a specific model or something my tension spring isn't green--is this something i need to do?

So its back together and is running pretty rough; I also hear a little valve clatter but that may have been there before? I haven't adjusted the ignition timing after changing the distributor o-ring.

In fairness it was running rough before I started the repair but ran well before the break down. The water pump had gone out on the highway and there was very little coolant left in the engine; I'm worried that there was some overheating damage. The thermostat went hot and the car stalled due to a blown ignition fuse. I replaced the fuse and it started but was running rough. At that point, I dove into the tB/water pump replacement...figuring that losing the pump may have screwed up the timing.

So here I am...I'd appreciate any advice on next steps---should I take the top TB cover back off and re-check the alignment. How crucial and or likely is it that the ignition timing is my issue following the distributor o-ring replacement.

Thanks your advice is appreciated.

[majones]

Just an update on my repair and current issues. Sorry for the long note but I would appreciate any advice.

I put things back together last night. I replaced the cam/crank seals, both idler pulleys, water pump, thermostat and the shaft seal and o-ring in the oil pump as well as the timing belt. I passed on the oil pump to block seal, I wasn't sure it was leaking. I also pulled the distributor and replaced the o-ring.

I believe the timing belt alignment went ok, but... I followed the manual supplemented with one of the DIY threads on the subject here. The TDC setting went ok, i think, the marks lined up and I rotated thru 720 deg twice to double check. The 0 mark on my TB cover is damaged but I can see the zero and guesstimated that the mark would be in-line with it. There was something in the manual about:

(d) w/ Green Tension Spring:
Slowly turn the crankshaft pulley 1 and 7/8 revolu–
tions, and align its groove with the mark at 45
BTDC
(for No.1 cylinder) of the No.1 timing belt cover.
NOTICE: Always turn the crankshaft clockwise.

I didn't do this, wasn't sure if this was for a specific model or something my tension spring isn't green--is this something i need to do?

So its back together and is running pretty rough; I also hear a little valve clatter but that may have been there before? I haven't adjusted the ignition timing after changing the distributor o-ring.

In fairness it was running rough before I started the repair but ran well before the break down. The water pump had gone out on the highway and there was very little coolant left in the engine; I'm worried that there was some overheating damage. The thermostat went hot and the car stalled due to a blown ignition fuse. I replaced the fuse and it started but was running rough. At that point, I dove into the tB/water pump replacement...figuring that losing the pump may have screwed up the timing.

So here I am...I'd appreciate any advice on next steps---should I take the top TB cover back off and re-check the alignment. How crucial and or likely is it that the ignition timing is my issue following the distributor o-ring replacement.

Thanks your advice is appreciated.

[toyomoho]

The verbiage about the green spring is for tightening the tensioner bolt.

Rotate the CW crank 1 time around then another 315 degrees to up the pulley mark at 45 degrees before TDC, then tighten the bolt.

The would be 45 degree before the pulley mark comes to the 0 degree mark on the timing cover.

You would be starting this procedure with the crank and cam marks lined as you did when you installed the belt.

To do a quick check of the belt installation rotate the pulley mark to 0 degree with the cam pulley lined up as to install the belt. The ign rotor should be pointing to the No 1 spark plug terminal on the distributor cap.

If your concerned about overheating damage might do a compression test. A quick test is listening to the engine crank over, the sound should be rhythmic not speeding up and slowing down.

[new echo owner]

Check, what toyomoho said!

N.E.O.

[majones]

I checked the compression and may have found the issue. Three of the 4 were 150-175 psi; the one closest to the timing belt was < 50 psi. For the low one, I added a small amount of oil to the spark plug hole but saw no improvement. Also seeing some evidence of coolant/oil mixing--white film on oil cap and oil? in coolant. Am I correct to diagnose as a head gasket and possibly valve leakage?

Any thoughts on my options and rough estimates of associated costs?

Thanks for your input.

[new echo owner]

Do a cylinder leak down test may help you narrow it down further, also a cooling system pressure test would help too.

N.E.O.

[majones]

I did the cooliing system pressure check. I pressurized the system to 20 psi. There was a slow loss of pressure but no obvious external leakage. I took out the spark plug on the suspect cylinder and re-pressurized the cooling system with no obvious difference to the test with the plug in; thought I might see coolant leaking into the cylinder?

A couple of other observations...when the car is running there are air bubbles coming out of the radiator overflow tube and what seems like more than typical moisture coming out of the tail pipe.

A question about doing a compression test. I followed the toyota manual...got the engine warm and took out all plugs and then tested. On the first crank for 3 of 4 cylinders I got ~150 psi shooting up to ~170 psi on the next 2-3 cranks. The pressure reading was always unsteady and went away very quickly when the cranking stopped. I hadn't done a compression test before so I'm wondering if the pressure should build and then stay or build on the compression stroke then go away? My cylinder closest to the timing belt had issues it never got above 50 psi.

I was looking for some procedural advice on the cylinder leak-down test. The tester manual says to warm the engine to normal temperature then pull the plugs and disconnect teh distributor connectors. Then it says to position teh cylinder under test at TDC...I know how to do that for the #1 cylinder but am unsure of an easy way to set the other cylinders to TDC?? My understanding is that after setting the cylinder to TDC (so that the valves are closed) I pressurize it note the leakage reading and for suspect cylinders listen for air escaping at the oil dipstick, radiator filler, tail pipe and throttle body. Does that sound right...any other helpful hints from someone who has done this.

Thanks.

[new echo owner]

Sometimes you might not physically see the coolant in the cylinder even if it is leaking, that is unless you have to means to look 'inside' the whole cylinder.

Compression gauges should have a check valve, usually in the hose to keep the pressure reading at its highest point. Check to see if yours is missing the valve or stuck, it is similar to a tire valve core. If the there is one cylinder consistently getting low reading, that might be the problem area that you should look into. The cylinder closest to the timing belt is #1 cylinder.

You can check what cylinder is at TDC by checking the dist rotor to see which cylinder it is pointing to, which ever one it is pointing will be the cylinder that is at TDC or close to TDC. Other than that, what you have noted is pretty close to what you will be looking for.

N.E.O.