Engine bound up
Asked by Slayer2132 Apr 24, 2017 at 08:03 PM about the 2001 Lexus IS 300 Sedan RWD
Question type: Maintenance & Repair
Why would the crankshaft only turns 30 degrees in
either direction after a timing belt install ? All
timing marks were set in correct position. I
removed the belt and then the cams to seat all the
valves. So with the belt and cams out, the crank
will only turns about 30 degrees. It sounds as if it's
hitting something in the rear of the block ( almost
like it catches the parking Pawl). The rear wheels
are off the ground and the transmission is in
neutral. I re installed the cams and spun them
around, so I know they're not hitting the valves
which tells me that the crank is in the right
position. Any help would be greatly appreciated.
Thoughts ?
30 Answers
Does the engine turn when you remove all the spark plugs? Did the belt snap before you changed it? If so you may have a broken or bent valve. You can use an inspection camera to look inside the cylinders.
What size engine is this? Like FOR is saying this could be an interference engine, and if the belt broke while the engine was running you could have some bent valves.
Slayer2132 answered 7 years ago
It was routine 90k maintenance. I drove the car into the garage. It's not the valves. Already verified that. Like I said, it sounds like it's hitting something in the back of the block.
I would double check the timing marks and make sure the engine is TDC compression stroke, not exhaust stroke for the #1 cylinder.
Slayer2132 answered 7 years ago
The timing marks are good. As for the compression / exhaust stroke, I am unable to do that because the crank will only turns so far. The cams were completely removed to verify that the crank was not hitting valves, so with the cams out, it would not matter what stroke it was on, you should be able to spin the crank, which I cannot.
enginecreator answered 7 years ago
Pull the oil pan. See if there is something in the bottom end binding.
Slayer2132 answered 7 years ago
I was hoping to avoid that but it is the next step. I can't see having an internal binding issue with the crank because of a t-belt change though. The car ran fine beforehand . The way it locks when you turn it seems to be coming from the back of the block, trans/ flywheel area possibly( not lower end ). I've seen another post in a forum where a guy had the same problem, unfortunately he never responded on what he found or if he fixed it. So I'm not the only one this has happened to.
enginecreator answered 7 years ago
Same thing there, how did a timing set replacement, cause the trans to lock up. With the timing belt removed will the bottom end move and when doing this timing belt procedure did you move the cam and crank pulleys around any, if so and belt did not break on you they should of been in the correct places to just remove it and install it. Last one I did cam only needed move over one tooth/degree as the belt had stretched a tad. If top end is not removed for any reason. If I do I make my own location marks.
Slayer2132 answered 7 years ago
Not saying the trans locked up, just saying when the crank comes to its stopping point when trying to turn it, you can hear a noise in that area. Best way to describe the noise I'm getting is like putting the car in the air and turning the rear tires when it's in park, you get that thunk noise when the trans hits the parking pawl. No pulleys were moved during the replacement of the belt. That's what's got me so baffled. I've done several of these and have never come across this.
Slayer2132 answered 7 years ago
And no, the bottom end will not move more than approx 30 degrees even with the tablet off. Cams will rotate just fine.
enginecreator answered 7 years ago
Yea I figured that out. With it raised and in neutral does the rear tires spin?
enginecreator answered 7 years ago
Is it AWD? I have heard of a few that were or least was said to be, so figured I would ask.
Slayer2132 answered 7 years ago
Initially, it was just the cam gears with the t-belt change to change the seals with the belt as well. I didn't remove the cams until I came across the binging issue. As stated before, it's not a trans issue, just the noise is coming from that area. Can't see all the bolts on the converter due to it not turning. I even backed the starter out thinking it might have locked up, but it did not help. I've done several of these when I worked for Lexus and have never run across this. These are very simple timing belt jobs. Just my luck.
Slayer2132 answered 7 years ago
@ enginecreator - yes the rear tires move freely in neutral. And no it is not an AWD.
enginecreator answered 7 years ago
I think since its interference engine that if you move the top end and bottom end then you will be able to fine the correct timing, when pulling the cam gear it may have got moved out just enough.
enginecreator answered 7 years ago
I still do not understand why the engine was moved in the first place. Or did you try to start it, then seen it would not if so or if you moved it then that is the issue to begin with, its either out of timing or has already done the damage of a broken belt.
Slayer2132 answered 7 years ago
@ enginecreator - on these cars, when you set the timing marks BEFORE taking the belt of, it puts the crank in the neutral position, so if the cams do move it won't come in contact with the valves when you pull the cam gears. After removing the belt and pulleys to replace the seals, the cam gears were reinstalled and we're still lined up with the timing marks on the back plate. The belt was reinstalled and I tried to rotate the engine by hand to verify the timing marks would line back up after two revolutions of the crank.....this is when I found the binding issue. Nothing was ever turned while the belt was off. As far as the cams/valves- when the cam gears are pulled out of the head, it releases tension on all the valves, allowing all of them to seat. With the cams out and all the valves seated, you can turn the crank all day long without hitting any valves. Now that being said, when I did pull the cams out to seat all the valves, the crank would still not move past 30 degrees. All the valve tips and Springs were all at the same seat hight, which tells me all the valves were seated and there wasn't one that was hanging up.
Slayer2132 answered 7 years ago
@ asktrannyman - it's not a valve concern ( please read one post above), all the valves seated normally. And the video link you sent is for the wrong 3.0 engine. The engine in the is300 is a straight 6, not a V6 ( thanks though).
Slayer2132 answered 7 years ago
@ Tom - I am the mechanic, please read the previous posts. Thanks.
enginecreator answered 7 years ago
I do not have the repair manual in front of me but do know that these engine have a step by step procedure, if not followed perfectly will toast the engine. Obviously you missed one and Internal repairs are needed.
Duh ,,, sorry dude ,,,,I'm missed the most important sentence ". I removed the belt and then the cams to seat all the valves. " however ,,, if it worked, you fixed it, then it didn't work ,, i suspect that many of us will keep our attention to what was done to make it not work .... I personally have managed to snatch defeat from the jaws off victory more than once
Can you take the valve cover off and verify what valves are open when the engine locks up ,,, put a feeler gauge between the cam a vave and if the gauge becomes so wedged you can't move it than you have found your cause of the engine issues. The advice of removing the plugs first is great advice
Slayer2132 answered 7 years ago
Took the cams out to seat all the valves. They all seated and the crank still would not move ( see approx 7 posts back )
Your right Slayer ,,,, I should know better than to jump conclusions when it's late and I'm tired ,,,, sorry I wish you luck ,,,,Tom
enginecreator answered 7 years ago
But like you said taking the cams out is after the fact it will not rotate more than 30 degrees and like ATM has pointed out the math is on the chalkboard already done, you missed a step and bent a valve. Pull the head off, bet it rotates all day long.
enginecreator answered 7 years ago
I am going to go ahead and say it. Slayer you have all the answers along with ours, make your mind up which to go after, pulling your own thoughts and answers out as if you did it correct and it has to be something else or finish the job and take it apart, you will see not only did we not see exactly what you did incorrectly but we know you did it wrong. Parts do not just fall to pieces for no reason.
Well said enginecreator .. We all have one thing in common and that's to help ,, there's a lot of talent here and we all have made mistakes because that's how knowledge is gained .
enginecreator answered 7 years ago
I have made mistakes too, just pick yourself up and try again. Thanks Tom
That there is something serious going on is self evident due to the fact that the engine does not turn. I would use an inspection camera before pulling the heads but my money is on bent/broken valves.