Weird issues...?

[denraweb]

Ok so I'm having some issues and haven't really dug deep to check anything yet, but going to tackle that today. Just wanna see what your guys' thoughts are.

Car is a 1990 twin turbo 5 speed 171k

heres whats going on...

I got the car from a guy that said the idler pulley was messed up. He fixed it and was going to keep it but decided to get rid of it. He changed the idler pulley and then changed a few coil packs. He said it ran fine when he did the idler pulley (I somewhat believe him 'cuz he has pics from after he did the idler pulley cuz he put new rims on it and took pictures at a big park thats far from his house), but after he had did something else, he said it began running rough. So he gave up. I have the car now, and bought it with possible damage in mind. It runs really rough, but starts and runs and drives. It has no power, almost like it's not getting enough spark or fuel (stock boost gauge barely moves while driving but BOV work). I tested all the coil packs and they are all about .9-1.1 (my voltmeter had a .2-.3 variable). I haven't tested the injectors yet or anything else for that matter. The weird thing is the RPM's don't reflect the rough idle other than being a little low 400-600, but they needle stays pretty steady. The whole car shakes, like you can see it lol. No smoke or anything. Could it be vacuum related? Timing off?

Also the car overheats. Doesn't blow smoke, but I did do a compression test:

Firewall
165 90
150 98
155 110
Front of engine

The guy said he changed the radiator (does look new) but didn't "burp" it which I know on hondas (what i'm used to) that can create an overheating issue. Anywho, I just change the radiator cap and am going to check more today.

[mrmoose]

90 and 98 are too low

[denraweb]

Yea figured that. My question is why only on that one side of the motor. I'm guessing head gasket...?

[mrmoose]

could be the head gasket or the cyls could just be bad... its weird because i had a car that had a whole side go bad, all the injectors on that side were bad, but only one cyl went bad. not all three. and a head gasket can have only one cyl go bad, in fact thats the case most of the time, but maybe some one did the gaskets and screwed that side up or didnt tq it down properly...

[denraweb]

Yea I'm gonna check the timing tomorrow and then all vacuum lines I'm gonna pull and redo to verify they are all right and then I'll find someone to do a leak down test and a pressure test.

[H1tman]

The belt might have skipped a tooth, probably when he replaced the pulley. You'll know if the CAS is maxed out.
The driver side cylinders have very low compression, maybe your battery drained a bit. Almost seems like your did the passenger side cylinders first and the moved to the drivers side. If you did you should it again but start with the drivers side. If not then its no bueno.

[denraweb]

The belt might have skipped a tooth, probably when he replaced the pulley. You'll know if the CAS is maxed out.
The driver side cylinders have very low compression, maybe your battery drained a bit. Almost seems like your did the passenger side cylinders first and the moved to the drivers side. If you did you should it again but start with the drivers side. If not then its no bueno.

Yea I'm hoping the timing is just off. The CAS (cam angle sensor right?) is the one on the further most cam (exhaust cam) on the driver's side right? The little slots where the bolts mount to (long slots for adjustment) are all the way to one side, which to me doesnt look right. I know on hondas, you turn the distributor to fine tune to help idle as well as detonation/retard. If the CAS does the same, then mine is way out of spec being all the way adjusted one way.

As for the compression test, I actually did the driver's side first. I also had jumper cables hooked up to my other car while it was running to make sure the battery didn't get low. The engine was warm, and it was a dry test. The car backfires some if I let it sit at idle and then tap the gas real quick. It will backfire just before the rpm jumps. If I let off and then let it idle and then tap the gas quickly again, it will do just the same.

Also I noticed today, the car only overheats if it's driven. If I just let it sit at idle, it seems to not climb anymore, but slowly starts going down. Once it's driven, the temp will start to rise again. I didnt get to burp the radiator hoses today.

[t.mcginley.jr]

Yea I'm hoping the timing is just off. The CAS (cam angle sensor right?) is the one on the further most cam (exhaust cam) on the driver's side right? The little slots where the bolts mount to (long slots for adjustment) are all the way to one side, which to me doesnt look right. I know on hondas, you turn the distributor to fine tune to help idle as well as detonation/retard. If the CAS does the same, then mine is way out of spec being all the way adjusted one way.

Yes that is the CAS. Like H1tman said the timing belt itself is probably off a tooth or so since the CAS is maxed out to one side (to try and make up for the difference).

As for the compression test, I actually did the driver's side first. I also had jumper cables hooked up to my other car while it was running to make sure the battery didn't get low. The engine was warm, and it was a dry test. The car backfires some if I let it sit at idle and then tap the gas real quick. It will backfire just before the rpm jumps. If I let off and then let it idle and then tap the gas quickly again, it will do just the same.

Most engine cylinders wear fairly equally, so having one side that far off from the other side sounds like a different issue. It's either the head gasket itself, the head bolts no being torqued down enough, or the cylinder head on the driver side is warped and not sealing correctly. Could also be an issue with valves not closing, but I doubt it since all 3 cylinders have low compression (110 is too low also, not just the 90 and 98).

Also I noticed today, the car only overheats if it's driven. If I just let it sit at idle, it seems to not climb anymore, but slowly starts going down. Once it's driven, the temp will start to rise again. I didnt get to burp the radiator hoses today.

It overheats when driven because the engine gets hotter under load. You can burp the coolant system, but it's probably not the full issue. If one whole side has low compression, AND the car overheats, AND has no power, it's an issue with the head gasket and/or cylinder head itself. This would also cause the low idle and the car shaking (mismatched power output on either side of the engine causing vibration). You might need to have the head taken off and checked.

[denraweb]

Yes that is the CAS. Like H1tman said the timing belt itself is probably off a tooth or so since the CAS is maxed out to one side (to try and make up for the difference).

Ok, I'm about to head out to go check the timing. Just so damn hot outside it's gonna suck taking off radiator and fan and all the parts to check the timing, but it's gotta be done.

Most engine cylinders wear fairly equally, so having one side that far off from the other side sounds like a different issue. It's either the head gasket itself, the head bolts no being torqued down enough, or the cylinder head on the driver side is warped and not sealing correctly. Could also be an issue with valves not closing, but I doubt it since all 3 cylinders have low compression (110 is too low also, not just the 90 and 98).

Yea I figured the headgasket was going to be an issue regardless.

It overheats when driven because the engine gets hotter under load. You can burp the coolant system, but it's probably not the full issue. If one whole side has low compression, AND the car overheats, AND has no power, it's an issue with the head gasket and/or cylinder head itself. This would also cause the low idle and the car shaking (mismatched power output on either side of the engine causing vibration). You might need to have the head taken off and checked.

As soon as I figure out whether the timing is right or not I'm gonna pull the valve cover and check the bolt torque on that head.

Would a leak down tell me more precisely if it's just the head gasket or something more? I've never had one done, just normal compression tests.

[denraweb]

Just a quick update... I pulled the radiator and when I did that, hardly any coolant came out of the hoses. There was a lot in the radiator, but I know in the past when I would work on a car and pull a radiator hose when it was cold, I would right away lose half a gallon or more of coolant just out of the hoses. Sound weird? Or is that normal? Could it be the guy just didnt put enough coolant in?

[H1tman]

Pull out the water pump and coolant pipes and you'll find out where the rest of the coolant is. Theres a drain plug for the block, try that.

[denraweb]

Pull out the water pump and coolant pipes and you'll find out where the rest of the coolant is. Theres a drain plug for the block, try that.

I pulled out the coolant pipes (both hard pipes) and only got about a drip total from both. Although there was a little seeping from behind the thermostat, which I left in place so I wouldn't have a big mess. It dripped for a few minutes and then stopped, still haven't pulled the water pump yet, as I still have the crank pulley on (prolly get it off tomorrow).


**UPDATE**
After pulling the timing covers, I rotated the motor by hand until I can get the 4 cams lined up as best as possible, and none of them are lined up. They are all about a tooth or two off. Even if the motor isn't at TDC, when all the marks are lined up on the cams, that should relate to the #1 piston being at TDC... I took some pics...

Crank mark...

Driver's side exhaust cam...

Driver's side intake cam...

Passenger's side intake cam...

Passenger's side exhaust cam... (used this as my "line up" mark)

[H1tman]

Yeah it's off. They will never line up EXACTLY but they should be really close. If you change the belt yourself make sure you line up with the cam sprockets with the marks on the belt and not on the rear timing covers.

[denraweb]

Yeah it's off. They will never line up EXACTLY but they should be really close. If you change the belt yourself make sure you line up with the cam sprockets with the marks on the belt and not on the rear timing covers.

Yea. I've heard the rear marks aren't very accurate. Tomorrow I will be pulling the crank pulley (hopefully it's been removed before so it's not killer to take off) at that point I'm gonna turn the crank until I get as close as possible to the original marks on the timing belt and cam gear marks. Then I'll be able to see how bad the timing is actually off. I'll snap some pics before I change the timing belt so I can post up.

[t.mcginley.jr]

You should still pull the valve covers and check the head bolt torque. If the torque is fine then it's probably a bad head gasket that's causing the low compression on the driver's side. Does the exhaust smoke at all?

[denraweb]

You should still pull the valve covers and check the head bolt torque. If the torque is fine then it's probably a bad head gasket that's causing the low compression on the driver's side. Does the exhaust smoke at all?

I'm gonna reset the timing and see if it will fire up and run and run good for a few seconds and then I'm gonna do a compression test again to see if the numbers were out of spec due to the timing. It doesn't smoke at all, nothing whatsoever.

[nissanfreak12]

Before you pull anything from the timing, count the cogs. Yes, the marks do not accurately line up, as stated earlier, just for reference. It very well could be on, but will not know until the cogs are counted. This is the only way to accurately do the timing belt check.

[denraweb]

Before you pull anything from the timing, count the cogs. Yes, the marks do not accurately line up, as stated earlier, just for reference. It very well could be on, but will not know until the cogs are counted. This is the only way to accurately do the timing belt check.

Which cogs are you talking about? I was just gonna put the crank to TDC and pull the belt and reset everything and replace the belt...

[H1tman]

Read the FSM, it's on here for free or google it. Cogs are the teeth on the belt. There should be a certain amount of cogs on the belt between each mark on the cam sprockets.

[denraweb]

Read the FSM, it's on here for free or google it. Cogs are the teeth on the belt. There should be a certain amount of cogs on the belt between each mark on the cam sprockets.

Ahh gotcha. Just did the the upper cogs. Passenger side head (intake cam to exhaust cam) 23 cogs. From intake cam to intake cam, 45 cogs. From intake cam to exhaust cam on drivers side, 24 cogs. Just loosened the crank pulley bolt, which came off with little effort, and I mean little, like 20ft lbs... So i'll count those which there are supposed to be 59. The cogs aren't a sure fire way since I never set the motor to TDC and most accurate way to do that would be the crank marks.. Which I am about to do. I'll post in a min.

[H1tman]

Wait..what? You never set it to TDC?

[nissanfreak12]

Yes, when you count the cogs, go mark to mark on each pulley. Look up the FSM, follow it to the letter when it comes to the timing belt. If this is set wrong will cause a ton of issues, running bad, overheating, poor power. The crank pulley will have a dot on it and a notch taken out of the oil pump. Those are the only ones that match up exactly, this is also TDC.

If you counted correctly, the passenger side is off, which I am sure you have already figured out. I would reset the timing and redo the compression test again, may not have to take apart the cams and test the bolts for tightness.

[t.mcginley.jr]

Not trying to threadjack I swear! But I have a question..

I'll be doing my timing belt soon and I know the procedure, but about counting the cogs... I don't know if it's just my brain not working today or what. I understand that if the timing belt is installed correctly, all lines on the belt will line up perfectly with the marks on the cam sprockets and crank gear. But say if the belt was installed one cog off, with the lines being one cog to the right or left on all the gears. Wouldn't there still be the same amount of cogs between gear marks? I feel like I'm missing something...

Feel free to fill me in!

[H1tman]

Yes. You could put on the belt with the marks 5 cogs off to the left, as long as ALL belt marks are 5 cogs off to the left of the sprocket marks they will have the correct amount of cogs between them. I hope you're not going to attempt this, you need to make as least complicated as possible when it comes to something as critical as timing.

[nissanfreak12]

H1tman is right, as long as all belt marks are x number of cogs off.

Timing can be a bit tricky, you need know what you are doing to do this. The lines on the belt are to help with reference, the idea is you match all the marks with the pulleys with the marks on the timing plate, crank pulley dot with the notch. Put on the belt with the white line matching the notches. After you set the tensioner against the belt, you should have xxmm, as per FSM. Rotate the belt to loosen all the slack in it like the FSM states. After all that is done, count the cogs, 24 notch on the passenger exhaust pulley to passenger intake pulley notch. 45 cogs from pass intake pulley notch to driver intake pulley notch. 24 cogs dv intake pulley to dv exhaust pulley. 59 cogs from exhaust pulley notch to the little dot on the Crank pulley. This can get tricky to count, so use like a mark every ten cogs, usually that makes it easier to count. After all is set, rotate BY HAND, if you have any resistance do not push through, possible valve and piston hitting. If you can rotate by hand at least 3 revolutions, you are good. Set back to TDC, and look at all the marks, you will see they will not match up, which is ok. They will be close.

I believe the numbers are right, but refer to the FSM for the correct numbers. This is also a quick break down on what to do, like stated before follow what the FSM state to do.

[t.mcginley.jr]

Thanks H1tman and nissanfreak

Sorry if I scared everyone, I do know the procedure and it's not my first timing belt job. I've been over all of the walkthru's and how-to's for this so I'm not worried. I was just talking more in theory... what I was getting at is if the belt itself only has a limited number of cogs (152?) then how does the timing get 1 or 2 cogs off? Or is this more because of the tensioner than the actual belt?

[nissanfreak12]

If the timing got off AFTER it was set correctly, could be because the tensioner went bad, created slack or the belt is old and stretched. Hope that is what you were looking for.

[denraweb]

Wait..what? You never set it to TDC?

Lol no that's why I stated that I would be pulling the crank pulley to verify TDC...

Yes, when you count the cogs, go mark to mark on each pulley. Look up the FSM, follow it to the letter when it comes to the timing belt. If this is set wrong will cause a ton of issues, running bad, overheating, poor power. The crank pulley will have a dot on it and a notch taken out of the oil pump. Those are the only ones that match up exactly, this is also TDC.

If you counted correctly, the passenger side is off, which I am sure you have already figured out. I would reset the timing and redo the compression test again, may not have to take apart the cams and test the bolts for tightness.

After pulling the pulley and setting to TDC via the mark on the crank, the passenger side was the only cam that was off. (passenger exhaust) and it was only off a tooth. I haven't compression tested again yet, but the car runs better, but still like s*** and powerless, nonetheless.

Not trying to threadjack I swear! But I have a question..

I'll be doing my timing belt soon and I know the procedure, but about counting the cogs... I don't know if it's just my brain not working today or what. I understand that if the timing belt is installed correctly, all lines on the belt will line up perfectly with the marks on the cam sprockets and crank gear. But say if the belt was installed one cog off, with the lines being one cog to the right or left on all the gears. Wouldn't there still be the same amount of cogs between gear marks? I feel like I'm missing something...

Feel free to fill me in!

I was thinking the same thing. It's just more of a reassurance thing that nissan did I think to help make sure everything is spot on.


So I redid my timing, as stated above, the passenger side exhaust cam was off a tooth (too far to the left). So I left it at TDC, removed everything and set all the lines and marks perfectly. After installing the belt, I turned everything to make sure nothing was hitting and it seemed well. I reinstalled everything and fired it up. Idle is smoother, and has maybe like 5 more hp as far as moving down the street, but still can hardly move down the street. Also I put in new coolant while the car was running, and it took the car a lot longer to overheat once driven, but I think I need to still add more as i'm sure the thermostat opened and closed enough to let more coolant in the motor.

Also I didn't mention this as it just crossed my mind (i dont think it will affect very much), but I am running a catless greddy evo2 exhaust, but with only one muffler. The passenger side greddy muffler was stolen, so that side is open. The driver's side is still there and bolted on. Couldn't really affect much could it?

Another thing is I have the stock precats. Are these just mini cats? Like can they get clogged and cause problems? I remember I went with my cousin to buy a car and it had lost power on the freeway bringing it home, but would start up fine every time it died. We couldn't figure it out until my uncle jumped in and slammed it into gear and got back on the freeway flooring it. Within like 10 seconds, a big a** black cloud came out of the exhaust and from then on, the car ran like a champ. Later we dropped the exhaust and found hundreds of pieces of the honeycomb from inside the cat in the exhaust and realized the cat was now gutted and completely hollow. Think it's a possibility as well?

[t.mcginley.jr]

No the one muffler wouldn't make any difference to the power of the car.

Yes cats can get clogged and cause problems. The stock precats are just an emissions precaution... like pretreating the exhaust before it even hits the main cats. On their own they are a big power restrictor, but they shouldn't cause issues such as no power. Most people replace them with aftermarket downpipes, which are just straight pipes from the turbo outlet to the midpipes (or test pipes if you have them).

Now that the timing is back on right, you should do the compression test and see what the results are. If still low on the driver side its a head gasket and/or cylinder head itself issue. let us know what happens

[denraweb]

No the one muffler wouldn't make any difference to the power of the car.

Yes cats can get clogged and cause problems. The stock precats are just an emissions precaution... like pretreating the exhaust before it even hits the main cats. On their own they are a big power restrictor, but they shouldn't cause issues such as no power. Most people replace them with aftermarket downpipes, which are just straight pipes from the turbo outlet to the midpipes (or test pipes if you have them).

Now that the timing is back on right, you should do the compression test and see what the results are. If still low on the driver side its a head gasket and/or cylinder head itself issue. let us know what happens

Yea figured the exhaust wouldn't cause much of an issue.

ALSO, i keep forgetting to mention, but I still have not checked the injectors!! I just thought about it. With that said, I noticed a few things after letting the car run in the garage. It left kind of a cutting onions feeling in the air... Actually more like when pepper spray is in the air. Stinging eyes, throat feeling like it's closing, etc. My dog noticed it as well, I had to run to open the door and let him in the house (yes the big garage door was half open). Then I ran back and killed the motor. Could this be like fuel being in the exhaust and burning out from the exhaust? Ive ran cars in the garage before, and other than the smell of the exhaust, I have never felt like that from a car running.