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View Full Version : 3.2 / 3.5 DOHC Isuzu Timing



LSAMS
07-09-2006, 09:13 PM
We have had a rash of these heads in our shop. It has been amazing to me how many times people call or come back saying we installed the cams wrong. I have researched and asked sevaral other shops including a couple head rebuilders. We all agree that our shop has installed the cams correct.
A few months back we had a 3.5 Isuzu engine in for a rebuild.It was for one of our regular garage customers. The rebuild went well, the engine was returned to the shop. A few days later they call and inform me that they had to send the vehicle to the Isuzu dealer to be timed. It cost them $300.00 and they felt like we should reimburse them. I agreed but told him he should have consulted with me first.
Now just this past week we did a 3.2 Isuzu rebuild. Again it went smooth.
The shop called me and said that the engine would only run on one bank.
They had exhausted all means of checking and wanted me to come by and take a look. I asked him to have the valve covers removed for me.
I spent an hour or so examining the timing, which was correct on the belt, but the actual valve timing was not right with the crankshaft.
Not really using my thinking cap proper, I asked them to remove the engine and return it to our shop so I could find the problem.
The engine arrived the next morning. I put my engine assembly guy on it right away. We removed the cams, pressed off the drive gears, inspected the dowel pins, they were intact. We reinstalled the cams, retimed the engine. As we rotated the engine through its cycles, the vale opening and closing was not right.
The timing marks on the belt and drive gears came right back to the proper place. We did this sevaral more times, consulted a couple diffent timing books. Made a few calls, but it seemed we were doing all we could do. I have just recently bought a book from Motors that covers all timing marks from 1965 to present. I decided to read the words and not just look at the pictures.
It hit me like a ton of bricks. I called my head guy, my block guy and had them to join me and my assembly guy in the engine room.
Its not really complicated, but it is a bit weird.
We all were amazed that the procedure was not listed any where else. I asume that Aldata and maybe Mitchell on Demand has it, but most techs are just like us and only look at the picture.
If any of you have experience a problem with these engines, I'll be glad to share with you how to do it. I am gonna ask the guys at AERA to add the instructions to the tech bulletin for these engines.

Dave Conway
07-10-2006, 03:31 AM
It would seem that most belt guides for installation do not cover the weird stuff. I have gone and got several different versions of installation guides and have found not all cover the complete timing sequences and installation procedures with respect to crank to cam(s) phazing. I found out along time ago after having to redo a 24valve toyota 3 times because the book was wrong because you had to turn a page in an attemp to get all the info. That book has since made a good fire log. But thanks for the heads up on that one.

rodeoaholic
01-29-2007, 01:11 PM
We have had a rash of these heads in our shop. It has been amazing to me how many times people call or come back saying we installed the cams wrong. I have researched and asked sevaral other shops including a couple head rebuilders. We all agree that our shop has installed the cams correct.
A few months back we had a 3.5 Isuzu engine in for a rebuild.It was for one of our regular garage customers. The rebuild went well, the engine was returned to the shop. A few days later they call and inform me that they had to send the vehicle to the Isuzu dealer to be timed. It cost them $300.00 and they felt like we should reimburse them. I agreed but told him he should have consulted with me first.
Now just this past week we did a 3.2 Isuzu rebuild. Again it went smooth.
The shop called me and said that the engine would only run on one bank.
They had exhausted all means of checking and wanted me to come by and take a look. I asked him to have the valve covers removed for me.
I spent an hour or so examining the timing, which was correct on the belt, but the actual valve timing was not right with the crankshaft.
Not really using my thinking cap proper, I asked them to remove the engine and return it to our shop so I could find the problem.
The engine arrived the next morning. I put my engine assembly guy on it right away. We removed the cams, pressed off the drive gears, inspected the dowel pins, they were intact. We reinstalled the cams, retimed the engine. As we rotated the engine through its cycles, the vale opening and closing was not right.
The timing marks on the belt and drive gears came right back to the proper place. We did this sevaral more times, consulted a couple diffent timing books. Made a few calls, but it seemed we were doing all we could do. I have just recently bought a book from Motors that covers all timing marks from 1965 to present. I decided to read the words and not just look at the pictures.
It hit me like a ton of bricks. I called my head guy, my block guy and had them to join me and my assembly guy in the engine room.
Its not really complicated, but it is a bit weird.
We all were amazed that the procedure was not listed any where else. I asume that Aldata and maybe Mitchell on Demand has it, but most techs are just like us and only look at the picture.
If any of you have experience a problem with these engines, I'll be glad to share with you how to do it. I am gonna ask the guys at AERA to add the instructions to the tech bulletin for these engines.

That's funny i should run across this bulletin. I am into a isuzu 3.2 now and found the same prollem. My manual had next to nothing on the weirdness of the timing on this puppy. I have since been advised to set the cam marks on driver side then rotate the passenger side back an 1/8 or 1/4 to compress the spring and then set the proper mark on the crank. Nowhere in any book did i get this info. I also am into a 97 rodeo and have found getting the crank pulley bolt off to be imposible. I have put 200psi impact on it broken a strap wrench with breaker on it broken a 24mm socket on it. Any ideas???

LSAMS
12-01-2007, 10:04 PM
Since I posted this message I have received sevaral calls from shops
looking for an answer. It amazed me how many have had a problem with this engine. Just recently one of our garage customers came in with the left head removed from one of these nightmares. He said the Customer came in for a waterpump and now three weeks later he has the head in our shop because he thought he had warped valves. As it ended up it was just the crazy timing ordeal. He just couldn't beleive it. He left our shop a tired and angry man. I feel his pain.

Dave Conway
12-02-2007, 01:48 AM
GOOD TO HEAR FROM YOU AGAIN LARRY.
Seems some things never change.:D

MikeT
04-29-2008, 04:27 PM
Larry
We have a 1999 Honda Passport that we did an overhaul and seem to have this timing issue. Its only hitting on the left bank. Its a 3.2 isuzu and we went by timing sequence in prosis.
Any advice would be greatly appreciated.
Thank You
MIke

gwdparts
04-30-2008, 01:15 PM
Had Same Problem With This Motor. Went And Bought Extra Large Drill And Modified 1/2 Inch Extension. Now All Motors Are Spin Tested And Checked For Comp. And Oil Leaks Before They Leave The Shop. Kind Of Like Using Poor Mans Simtest.

MikeC
04-30-2008, 03:02 PM
Larry,
Please Look at AERA TB's TB2143 & TB2144 made in 2004. Since that time everyone said the TB's do the job if they do not let me know.
Mike

MikeT
05-10-2008, 08:07 PM
Ok, I went by TB2143 and TB2144 and went from engine hitting on drivers side. To will not start. The cams and idler gear are lined up correctly. The only thing i'm not sure of is that the timing belt gears on the heads have three marks. One line and two u shaped marks. None of which shows any green. What am I missing ?????????

MikeC
05-12-2008, 10:23 AM
Mike,

What year vehicle?

Mike

MikeT
05-12-2008, 10:57 AM
Mike
It's in a 1999 Honda Passport.
Mike

MikeC
05-13-2008, 06:35 PM
Hi Mike,

Glad you got it straightened out. Turning the drivers side cam sprocket + 90 making the marks line up made it all work. Thanks for the call back.

Mike :)

JohnG
05-14-2008, 11:41 AM
Mike Caruso:

Do we need an AERA TB on this or just modify the one we have now?

John

MikeC
05-14-2008, 05:29 PM
John,

TB's are ok just have to line up the drivers side cam sprocket which takes rotating the cam sprocket with valve spring tension fighting you until the timing marks are lined up.

Mike ;)

lionking46
10-05-2010, 02:39 PM
John,

TB's are ok just have to line up the drivers side cam sprocket which takes rotating the cam sprocket with valve spring tension fighting you until the timing marks are lined up.

Mike ;)

Thank you Mike Im on my way to installed

LSAMS
12-03-2010, 06:05 PM
Mike Caruso:

Do we need an AERA TB on this or just modify the one we have now?

John

Hey John, I think you need to at least add some info to the AERA TB. It needs more detail on positioning of the cams, or rather the sub gear that drives the cams. I have had maybe 15 calls from all over the U.S. since I posted this. Just make it clear about turning the sub gear to the right place. Keep up the good work guys.

AutoTechofCrowleyLA
12-28-2010, 11:26 AM
I found this on the net that helped me alot on this job.
http://www.enginebuildermag.com/Article/58708/19982002_honda_32l_v6_camshaft_subgear_preloading. aspx