EJ timing

I am having an issue with a subaru ej20 cam belt timing . I am chassing a strange overheat issue which might be the head gasket but started by replacing the water pump . Now before I took the belt off I brought the timing marks as normal and it looked like the left intake cam was off by 3teeth . I repalced the water pump and followed the oem specification according to the manual that I have in pdf . The manual states thst you have to count 28 teeth between the intake mark and exhaust mark per side . I managed to do this and the timing marks always fall into place which I believe is a good thing . Yet in my struggle to do so I found multiple videos stating that you just time it to the belt marks release the tensioner and leave it as is as the marks will not fall into place due to the number of teeth etc. . Now my concern is since I always have the marks falling into place have I done it wrong or not . Would like to hear from more experienced people than me on the ej engines .

Also the overheating issue that I have is that while bleeding the engine fans will come on but not turn off . You take it for a drive 1 day it will work properly another day fans will go on and not off reaching max temp of 110C even on the freeway . In traffic it might get up to 95C and drop but on the freeway its always at 105 to 107 occasionally 110C

So it doesn't matter what position it was in when it comes off, what matters is what position its in when it goes back on.

Always start by ensuring the crank is aligned with the TDC(top dead center) mark.

First, its a good idea to use a tool to lock the cam gears on the right side (if your looking at the front of the motor). These will be under tension and spring back. https://www.company23.com/subarutools/506 Company23 make a good one

Theres a few ways people do this, my preference is to put all the pulley's on, leaving the tensionor pin in, but leave the small idler next to it off.

Each cam gear will have two different markings.

a single line, this needs to align with the mark directly on the timing cover. For the intake cams gears this is on the top.

For the exhaust, its on the side.

Next, there is a double line on each cam gear. This needs to align with the other cam gear, eg the two marks on the intake cam, line up with the two marks on the exhaust cam gear.

Once everything is lined up, put the belt on the crank first, then work towards the left keeping the belt taught as you go

Once you get to the tensionor, if you've keep the tension on the belt. Everything should be lined up, and the slack should be at the tensioner.

You can now put the small idler on, and pull the pin out the tensioner.

Then rotate the crank clockwise slowly (double check the manual before you do this to make sure you only go in the one direction)

Once the crank has done two full rotations bring it back to TDC. In theory, all the cam marks should line up. single lines and top or side. And the double lines should be spot on.

I usually like to then do another two rotations to be sure.

Then you can put the belt guides back on, ensuring a small amount of clearance, i use a piece of thin carboard usually as feeler gauges tend to leave the guide wonky when you tighten it up.

Now there's a catch, if your engine has been apart a few times, you may find that the timing belt will never line up, often on one side. This is because every time you shave some material off the block or head surface, the engine becomes narrower. And will affect the cam timing. You will then spend ages re-doing timing only to find it will never line up. In that case, you can replace two idlers with eccentric ones that allow you bring it back into alignment. IAG make them, as do a few others.

On the temp\fan issue. How are you measuring that temp? are you using the factory sensor or do you have an aftermaket one?

It sounds like you have a air pocket in the coolant system. Subaru's are extremely sensitive to this. Are you loosing coolant? Can you see any leaks?

Is there coolant filling up the over flow bottle?

And how are you bleeding it? Again there's some subaru specific tricks to this to ensure you get all the air out

Thanks for the reply . I have done quite a few engines but it was my 1st ej . Before removing a timing belt I usually bring it to where the timing marks are so I can see if previously it was timed correctly etc. . I always rotate them once I have finished as you mentioned .

Now I have bleeded a few subies with no issues . I fill the radiator (it it has a cap) and then fill the coolant tank above the intake. I also use a coolant funnel . I have tilted also the car at the front to have a higher point .

Just also check they have the right cap. They aren't the same

One cap is specifically for the radiator and the other is for the expansion tank (on intake). And while you can put them on either spot, as they fit. They are sprung differently.

Usually the round cap goes on the radiator and is essentially a high pressure relief valve. The winged cap, goes on the expansion tank and is the coolant system pressure regulation cap.

If you get them backwards you can end up with a air bubble lower in the cooling system after it gets hot.