You said that one time, after being asked many times.

Machine shop charges for a valve job vary from region to region. Your best bet would be to call them in your area. It also depends on how many valves are damaged and if there is any other work needed on the head.

 

oblidi. oblique? oblivious? oblivion!

 

Hi,

You asked hoe this is supposed to work, here it is.

It appears to me that you may have moved a few things, and then forgot exactly what you did. That's OK. Here is how it is supposed to work. First of all, the cam and the spark rotor rotate ONCE, for each time the crank rotates TWICE. So, let's assume you randomly rotated these things and now don't know where they belong. There are marks for top dead center of cylinder #1 on the each of the cam gear, the rotor gear, and the crank. You need to get them all lined up to their respective marks. Hopefully, you didn't damage anything if they were all wrong when you tried to start the car. Did anything make a loud banging sound as you cranked it? With a Volvo engine, it can happen if it's too far off but I hope it's still OK. You should always carefully turn the engine two complete revolutions by hand with the spark plugs removed after you're done whenever you change a timing belt to verify that nothing is going to hit or bang so you don't do any damage when you crank the engine.

The new belt should have marks on it. They are redundant, if the gears were truly in the correct spot, and didn't shift as you apply tension to the belt, you wouldn't need them. They are there because it is sometimes difficult to look at the correct angle to line up all of the marks exactly and the gears might shift when you apply tension to the belt, so they make it "fool-proof". Now if after the gears are lined up, and the belt marks don't line up, then perhaps you need to reorient the belt so that they do.

OK now that the belt is under tension, if you carefully rotate the engine just slightly you should be able to verify that all three marks on the belt are lined up with the marks on the gears. Now tighten the tensioner per spec and everything should work.

If you're still not sure.... here's a good test. Remove spark plug #1, the distributor cap, and the oil filler cap. Rotate the engine by hand so the crank timing is at TDC. Nothing should bind or bang other than the resistance you feel due to compression of the cylinders while you do this. Look at the rotor, when it is pointing to spark plug #1, the piston should be the closest to the spark plug hole (that's what TDC means). Also, look at the cam lobes for cylinder #1 valves, they should be symmetrically away from the valves. The timing mark on the crank should be at TDC. Rotate the engine one whole revolution, the crank mark is again at TDC. Check the rotor, it should be pointing 180 deg away from spark plug #1. Look at the cam lobes... this is critical, they should symmetrically switch from the exhaust to the intake valve. The center of this symmetry is at TDC. If all this is correct, then the belt is correct and it should start.


Keep us posted.

HG

 

Thank you so much HG.

This is exactly the info I've been hoping to hear.You are a gentleman and a scholar. I will keep you posted!

 

Maybe you can offer something useful. Doubt it.

 

So where's the"nice" in these replies. I am curious to your qualifications. I have a sense that all you do is repeat all the other posts that describe my situation. I don't think you or EST6 have a clue on how to fix this. Read the last post from HG. It's a point by point instruction on how to reset the cams. This was all I was asking for.

 

Easiest way to check the cams.

Set the engine so the timing marks are right on then take off the cam pickup and distributor. The cams should look like this:

 

Haha so the "nice" reply with wrong info gets the appreciation. The timing is not set at TDC. There are no marks on a new belt. And good luck seeing the cam lobes for number one or any cam lobes for the exhaust cam.

My qualifications? Volvo Expert level tech with over 10 years experience working on nothing but Volvos. But what do I know?

Pull the head. You trashed the valves. It's really that simple.

 

Hi,

I may have mis-read your post. I thought your car was a single cam one. It is twin cam. It is slightly different as I described but the same principles apply. There is no magic sequence for the relationship between the cams and the crank. As long as they are on their marks and the crank is on its mark when the belt is installed, it is correct. Getting there makes no difference, BUT when you move the cams or the crank independent of each other, you must be careful that a piston doesn't hit a valve on your way there.

This engine has some very tight clearances so if it is wrong, then a piston can hit a valve and ruin the head (and possibly other things). I'm going to be an optiist, and assume that you didn't damage anything, and are only off by a small amount. So the first thing to do is find out if this is true. Take out the spark plugs so we don't work against the compression and carefully rotate the engine with the belt on as it is right now by hand TWO complete revolutions. If nothing hits, then chances are you didn't damage it yet, otherwise, it would still hit, or make some other bad sounds. Do this slowly and carefully in case something does hit inside.

Just because it is quiet doesn't guarantee nothing was damaged, but your chances of it not being damaged are getting better.

If something is hitting then it was also hitting when you tried to start it and as the others have said the head is ruined.

OK if everything is good, carefully rotate the engine until the cam marks line up. Are they both cams lined up and the crank? If they are, then your problem is elsewhere. If it is slightly off, sometimes one tooth off might cause it not to start (although I would expect a cough or a backfire) you can remove the belt as before, and line everything up and replace the belt.

After the belt is completely installed, rotate the engine by hand again TWO revolutions and verify that the marks all align. NOW you can fire it up.

As far as niceness, all of us on this forum should keep in mind that all of us are learning something new every day and need to be courteous and patient with each other. It is difficult enough to be under a car on a cold day with oily mud falling in your face and you wife asking "why isn't it fixed yet?"

As far as qualifications? I am not a mechanic. I am a retired electrical engineer that is now a part-time physics professor and I love rear wheel drive stick shift Volvos, and do all my own work.

Keep us posted.

Cheers!!

 

Ten thumbs up.

 

Thanks for you reply. IO happen to be at a disadvantage with a learning disability. Somethings I get, and some things don't make sense to me when it makes sense to others. Yes, the concrete floor of my garage is very cold but I've been making repairs under many BMW's,Volvo's and MG's.I appreciate your kind words of patience.
So, with your advice, I removed the plugs, Dropped a long screw driver into Number 1 cylinder and rotated the cranks several times till the screw drive reached it's utmost height. Then I moved both Cam pulleys to there proper timing positions according to the timing cover marks. I'm still compressing the tensioner. I should have something to report tomorrow when I pull the pin and try to start it. In the mean time, I'm also replacing the flex disc on a 318ti BMW, and preparing a '77 MGB for its winters break. Oh yes, the Explorer needs a belt and assorted parts.
My thanks for your kind words of patience. As for the others, Learn to be patient. You just don't know who is asking for your help. A very Happy Christmas to each and all of you. Dr. Oblidi

 

NO!!! The Volvo engine does not set timing at TDC, it is off a few degrees. You cannot set timing based on the height of the piston, you will be off. You must go by the mark on the crank or get the tool that goes in the side of the block.


This is a picture of a piston set to the timing marks. Its a few degrees negative



This is a picture or the crank at TDC, its a full tooth off.




The timing tool

 

Yep, you don't know who is asking for help. And you also don't know who is giving help. So you can keep trusting the guy with the better bedside manner, but that will have you taking the long way to pulling the head because you trashed the valves, like I said days ago.

 

Hi Oblidi,

So, now that you have rotated the engine, did anything hit? Is it still OK? Hopefully you didn't hear any broken pieces rattling around. Pay attention to what Boxpin said. When you put on the belt, ALWAYS line up everything using the MARKS, not TDC. I only suggested you find TDC on the crank (like you did by finding the piston position) to get you close to the mark. The mark can't be too far away, so now you should be able to find it. BUT USE THE MARKS.

I also suggested you do find TDC because you said you may have rotated it way off and I figured you might be unable to find the correct mark. Yesterday, I also mistakenly suggested that you also look at the lobes on the cam, but that was when I thought you had a single cam engine like my B230 (a much easier engine to work on).

Finding the piston, gets you close. Now you need to find the actual mark. Look at the pictures Boxpin has given you from all his posts. You will probably need to move the crank slightly to line up the actual mark (like Boxpin's pictures) and then install the timing belt. I am assuming that you also have the cam gears lined up to their correct marks. Listen to what Boxpin tells you, and hopefully it isn't as bad as ES6T thinks it is. He still could be right, but lets make sure once and for all with everything lined up and see what happens. Also, to save time, once the belt is on and properly tensioned, do another compression test to see if the numbers look more reasonable. If not, then you either still don't have the marks lined up (maybe you're looking at a rust spot or dirt on the gear and think it's a timing mark) or ES6T was right all along.

It's not a point of bedside manner, it's a point of exhausting all possibilities to be absolutely certain before we rip an engine apart. We've gone this far, let's go a little further to be absolutely sure the head is bad before we take it off. As far a who's giving advice, ES6T and Boxpin have far more experience with these engines than I have, so listen to what they tell you. I use my engineering training to investigate and test things and I don't rely on "what usually happens" but rather come up with conclusive tests before I make a conclusion.

For some of us, it's easier to go through the timing belt procedure a few times even if it's for nothing and it's still not fixed and find we have to take the head off anyway than it is to take the head off and then find that we had done something else stupid and we didn't need to take it off after all.

For others with much better equipment and experience than I have, it might be as trivial to remove the head as it is for me to change a tire, so for them this extra testing is a waste of time.... they would just pull the head and they would be correct, because they would make an improvement by cleaning the carbon on the pistons, doing a complete valve job and with a new head gasket, that's like a new life insurance policy on the head gasket.

Have a Merry Christmas guys. Let's not forget to thank Boxpin and ES6T for their expert advice. You may need more of their help if you need to pull that head.

Keep us posted.

Cheers,

HG

 

I knew I would be missing something by being away for a few days while traveling. Very entertaining information here. LOL

Here is my take, with video's in their respective order.

1. If you cranked the car with the timing off far enough to damage valves, it's like a high blood pressure stroke, silent killer, you won't hear a thing.

2. If you are in the process of doing a basic replacement of the timing belt, and not trying to fix a situation due to a failed timing belt, there is a good chance that you are fine. As explained several times, the belt is to be installed according to the marks only.


3. The crank has a mark and the cams have marks. When the CRANK is on it's mark, and the belt if off, you can rotate the cams in either direction 360 degrees with no valve contact or issues. I would NOT try to turn the crank 360 degrees with the cams on spot, that is a different creature. Get the crank on mark and move the cams.

4. Here is a timing alignment check:

5. Timing information with head removed:

6. There is a proper way to check compression, from what I have read above, it has not been done. DO NOT think that you did a good compression test. FUEL and/or WATER are NOT things you want to WET a test with. Fuel actually can WASH DOWN a cylinder wall and cause a ZERO compression situation. Because of this... you may now have a LAWNMOWER SYNDROME. There is a good chance that the car is NOT starting due to low compression with NO PHYSICAL damage. Try this after you dry out the cylinders (somehow). You should try to start it once normally, then try to start it again, after you push the fuel pedal to the floor before you turn the key.

Last but not least, the CRANK turns twice to every one turn of the cams, as explained. HOWEVER, every time the CRANK goes around 360 degrees, it is IN it's proper TIME and NOT 180 degrees off. The CRANK makes a full revolution every time it is turned around to it's mark.

 

Oh, here is a compression test video. If you use fuel to WET your compression test, you likely cause LESS compression to build because fuel will WAS DOWN the cylinder walls and contaminate the oil in the pan. So, you likely need an oil change as well.

 

Now for my negative side... if the car is NA, and the head is damaged, just crush it. Get a turbo, a lot more fun to drive.

 

He screwed up the engine and won't come forward with the whole story. Doesn't sound like he lined it all up before removing the belt.

My suggestion is to enjoy your mess.

 

Right. But, if you leave the crank and turn the cams 360 degrees, they are 180 out. That's why it wouldn't start initially. By now, he has turned the cams to who knows what position.

I'm not going on "what usually happens". I'm going on what ALWAYS happens when an interference motor is started without correct timing. You can't pull the belt, move everything to whatever position you want and then fire it up.

 

You are killing me with this "360 degrees" thing. Stop joking with the poor guy. He thinks you're serious.

P.S. None of my volvos have cam timing marks.