99 V70 confused on TDC timing

[russloyd]

short story...
i had to replace the front cam seals on my 99 v70 BASE (no turbo, no AWD). everything went swimmingly until the cam lock tool slipped thus causing the cam wheel (not sure of term) to slip when i was breaking the three bolts free. I tried my best to put them back into the spot that I had marked, but upon reassembly (and subsequent start) I now think that the timing is off.

following the reassembly, the car started well. it was slightly "slow to start" but not by much. I let it idle for a bit while i checked for the seal leaks, etc. seemed to idle fine. I did this 2 times with no noticeable problems. On the 3rd time I was going to drive it up the driveway and around the block. driveway is ~120 ft. going up the driveway it was sputtering pretty bad. i backed it down and back into the garage.

so...i have read almost all of the threads on TDC timing on volvos, but i am still confused about the best practice here. I need to realign the the cam heads from scratch.

my understanding is that
1. there is no true TDC on a Volvo. at least based on the postition on the crank
2. I should start with the crank (at the bottom of the engine) and align that first with the marks on the wheel.

from here I am confused. should I be looking at the driver side of the cam shaft (the side where the cam lock installs) and aligning those slots in the 10 oclock (LEFT - bumper side) and 2 oclock (RIGHT - firewall side).

?


Then moving to the passenger side of the engine and set the cam shaft wheels in alignment with their marks on the timing belt cover?

if someone can please (pretty please) help me with a definitive answer on how to set the timing from scratch, i would be forever grateful.

i already am grateful to all of the pros on this forum. you are all BA Baracus. Thank you.

[Ozark Lee]

On a '99 the camshaft timing marks should be at the 12:00 positions. That is for sure on the turbos and I think that is the case with the N/A engines as well. On the '99 N/A you don't have CVVT so all you need to do is center the camshaft sprocket at the center point on the slots for the three bolts and line the camshaft scribed marks to the reference points on the cover. That, of course, must be done with the crankshaft lined up to its mark.

To make double sure you can check the back slots on the camshaft to make sure they are horizontal and lined up with the seam on the cam cover. That is fairly easy for the exhaust camshaft (just remove the camshaft position sensor and its trigger wheel) but the intake camshaft has a tap in cover and no seal behind it. That cover is very difficult to pry off without damaging it.

...Lee

[russloyd]

Thanks Lee! so to be clear.
in regards to the position of the camshaft, I was asking about the grooves on the driver side of the camshaft (the side where the cam locking tool connects). the reason i ask is because my camshaft wheels/sprockets (passenger side of engine) did not have any factory calibration marks that i could find. (i looked several times, for a while) I do see the notches in the timing belt cover are at 12 oclock.

Lee... "On the '99 N/A you don't have CVVT so all you need to do is center the camshaft sprocket at the center point on the slots for the three bolts and line the camshaft scribed marks to the reference points on the cover."

can you elaborate on the center point on the slots for the three bolts? i am not sure that any mark on the wheel/sprocket would matter at this point because i assume they were installed incorrectly. is there a mark under the wheel/sprocket on the shaft itself where the three bolts attach (where the seal goes)?

http://bit.ly/1uyD4bA - my camshaft wheels look like this. What is the "M" mark for on the wheel? i surely don't see any alignment marks on the teeth.

i am asking if i need to be looking at these (Link below) in order to properly align it with the crankshaft.
http://bit.ly/14zncvD

so...first the crankshaft, then these things pictured above (the camshaft where the 3 bolts attach), then replace the camshaft wheel/sprocket in the proper place in relation to the notches in the timing belt cover...?

thanks a ton!
____
PS - this car is one of those hybrid 98/99 v70's. the engine is clearly stamped 98. but all of the parts and such fall under the 99 model. the VIN pulls a '99 number as well.

[erikv11]

Since the cam sprockets came off, the bit about "center(ing) the camshaft sprockets ..." is a way to guess about how they came mounted on the cams from the factory. It is definitely only a guess, so if you have some good information remaining from your markings then that would take priority. There is no mark under the sprockets, FWIW.

For the same reasons, the M mark is not relevant to setting the timing. The sprockets can go on in any orientation at the factory. If there are stamp (timing) marks, those were the very last thing that was hand-stamped on the sprockets at the factory, after the engine was assembled.

Since your car does not have VVT:
(1) Put the crank on the mark.
(2) Align the rear slots on the cams exactly parallel to the sealing surface of the head, intake above exhaust below, use the cam lock tool if you have it.
(3) Replace the sprockets, as stated use your marks if there is info to be gleaned from them.
(4) Set the timing belt.

That should do it. If you want to get really meticulous, you could follow that with this:
(5) Turn the engine over a couple revolutions by hand with a socket on the crank pulley (OK you should do that anyway!) until the crank is on the mark again. Are the slots on the cam rears still parallel and in line with the head? They might be off a little, if you didn't get the cam sprockets on just right. You can perfectly hit the factory timing now by loosening the bolts on the cam sprockets, and with the timing belt in place *rotate the cams from the rear* while leaving the sprockets alone. Make the cams perfect, then tighten the cam sprockets, the repeat step 5 to check again.

Note: the cam sprocket bolts are really low torque, don't overdo it.

[rspi]

These cars, as with MOST newer cars DO NOT use piston location to align timing nor use timing lights. Clear your mind and focus on marks.

As for the comment about centering the bolts in the cam sprockets slots, the cam sprockets have slots where the mounting bolts attach. If you loosen all 3 bolts, with the belt off, the cams can be pivoted a little allowing the bolts to slide in Tue slots. I'm pretty sure Lee was suggesting that you center the cam bolts in the slots to begin your timing process.

If you are going to verify timing on the back of the cams, you may want to loosen those 3 bolts, align the cams on the back of the head, secure the sprocket bolts, make your own marks with a file or white paint, then close everything up and press forward from there.

[russloyd]

sweet. all of this is good info erikv11, rspi & Lee. thank you!

to answer your question...when i originally put it back together the rear cam notches (driver side) were parallel with the head. at least really close, but i was only assuming that the crankshaft was in the correct place as i did not turn it except with the timing belt connected. also i did not turn over the crank by hand before i started the car the first time.

IF the firewall side, rear cam shaft has three notches instead of 2 (can't remember) that 3rd notch should be somewhere around 4 oclock in relation to the other two notches being parallel with the head, correct?

[erikv11]

Sounds good, the timing should be at least close. But maybe the crank was not quote on the mark? If you put it on the mark now, you can check the cams. If they are parallel with the head then the engine is in time.

Cranking it over by hand is so you can check the marks again, sometimes a cam slips etc without you knowing it, so timing will be off even though you thought you did it all correctly.

I like rspi's suggestion to mark the sprockets once you get it all zeroed in. Then you won't have to go to the rear of the cams all the time, it would get tiresome!

EDIT: this info applies to a 93-98 engine, yours may or may not be the same as you pointed out: I've never seen three notches on the rear of an exhaust cam. But the little metal brackets that screw into the ends of the cams have asymmetry. The distributor one (intake or front cam) has a notch that sits at 4 o'clock, the cam position sensor one (exhaust or rear or firewall cam) has a rim that goes from like 2 to 7 o'clock.

[erikv11]

Here are the cam slots, from the inimitable Tracey's head gasket tutorial (Volvo 5-cylinder: How to Replace the Head Gasket)

[broken images removed]

[Ozark Lee]

Robert was correct on what I was trying to say on centering the sprocket bolts.

It is actually a fairly minor point but the cam timing on the pre CVVT engines was adjustable over a few degrees either way by adjusting the relative position of the camshaft sprocket on the camshaft itself due to the slotted bolt holes in the camshaft sprocket. It is the kind of thing you would play with on a Dyno trying to eek the last couple of HP out of the engine in a given RPM range. The safe place to set that "adjustment" is centered on the slots on the bolt holes. Just eyeball it, it doesn't need to be dead on.

The pictures Erik posted from the Tracy's tutorial are exactly what I was referring to with regard to the back side of the camshafts. If you are totally lost on where the cam timing is that will get you where you need to be every time.

Can you post pictures of your camshaft sprockets? We might be able to spot the timing marks to help you out with some pictures. You might also try using chalk around the toothed edge of the sprockets to try to highlight the marks. They are often very faint but once you spot them you know it.

...Lee

[russloyd]

I have aligned the marks on the crankshaft. I put the mark on the block in between the 2 marks on the crankshaft teeth. With that aligned, the notches on the rear of the camshaft (drivers side) are parallel with the lines of the head (see the pics linked below). one concern I see is that that in Erik's picture of the notches on the front camshaft, he notes that the notch groove is above the head. On my car (a) I have 3 notches on the front camshaft with the 3rd notch being at 4 o'clock and (b) the front camshaft notches that are parallel are BELOW the head. The rear camshaft is parallel but ABOVE the head line.

so, I am super confused as there is no way that I was 180 degrees out. I can not imagine how that would happen.

my question is should I turn each camshaft 180 degrees? so that the front notches are ABOVE the head line and the rear camshaft notches are BELOW the head line?

rear pic
https://www.dropbox.com/s/m7usx22048q2l ... 5.jpg?dl=0

front pic
https://www.dropbox.com/s/o2ve45ybuwvn4 ... 9.jpg?dl=0

please remember that this is one of those hybrid 98/99 volvo's. the engine is stamped 98 but the VIN and parts that fit the car are 99.

thanks all for your help.