: head gasket help!!!!!!



lacycosmo
11-12-09, 02:31 PM
Believe it or not we replaced the head gaskets on a 4.0 northstar engine. however, we cannot get the timing chains back on. the tension is too tight. Does anyone know how to adjust the tension? we really dont want to take out the motor. any ideas are appreciated:banghead:

tateos
11-12-09, 02:49 PM
Well - obviously you need to press the release lever and depress the plunger on the tensioners - are you doing that?

lacycosmo
11-12-09, 03:14 PM
well i dont know where the plunger is located. sorry this is the first time we have done this all ourselves. We couldnt afford to take it to a shop so we are kinda flying blind here can you help?

chacenbra
11-12-09, 04:36 PM
On the side of the motor (opposite the trans) is the timing case, within that case there is a series of guides, sprokets and tensioners when you look at these tensioners you will see a small release lever (as tateos is describing) press that lever towards the tensioner and depress the plunger, now look at the release lever you will see that there is a small hole in the lever place a pin through that hole to keep the plunger from jumping back out.

Once you get the chains all in place pull that pin and your chains will be tensioned.

Now one thing that concerns me is you let those tensioners all the way out the plunger may have come out of its socket, if it has REPLACE the tensioners, when I did my job I tried to put one back together and after I got the car all put back together and hit the key I began to hear the chains slapping around, I then had to replace them with the motor in the car (not a fun job AT ALL)

Note: you will need a 3 Jaw puller to remove the crank damper pully. (there is a special tool that GM uses I believe but a 3 jaw worked great for me)

MrEldo97
11-12-09, 04:51 PM
After you reset the tensioners and timing chains turn the motor over several times by hand;TDC on compression stroke to TDC on compression stroke (use socket on crank pulley nut to turn) and check to be sure that the timing marks line up. What's the ratio - two crank revs for every cam rev...? It's not just a matter of setting the timing chains once and forgetting them. You MUST assure that you set them properly and the timing doesn't vary - No.1 piston TDC and all timing marks line up.

lacycosmo
11-12-09, 05:32 PM
thanks we will give it a try

zonie77
11-12-09, 05:50 PM
Guys have done it in the car before but it's the hardest way. The timing cover has to come off and at TDC on #1 the timing marks must all line up. There are threads with diagrams or you can usually get a factory service manual on ebay.




Did you insert the head bolt holes or use the studs?

tateos
11-12-09, 06:36 PM
Is the engine in the car? If so, some people have written that they were able to unbolt the timing case cover and slide it back far enough to depress the plungers and avoid removing the crank damper. To remove the damper, I think you will need to drop that side of the cradle down some, to gain access.

chacenbra
11-12-09, 06:55 PM
I pulled my damper without lowering the cradle in my 99 DeVille.

bigtone
11-12-09, 09:00 PM
I did my H/G in the car, and all I had to do was remove the timing cover bolts. The cover will slide back enough to get in there and retract the tensioners. I used 2 of those orange handled picks that you find at the discount tool place, and I custom bent them to fit in there just right. If I remember, I used a long craftsman screwdriver stuck down though the opening in the head where the chain comes through to push the shoe back while the pick was holding the release lever. While they are retracted, slide the cam gears on the cams. When the engine is at TDC on #1, the marks are exactly 90 degrees perpendicular to the head surface. To double check, after I installed the chains I turned the engine over by hand a few times to make sure the marks were lined up right. Then I spun it with the starter to check the cranking compression. If I was off a tooth, the cranking compression should be off on one bank.

tateos
11-12-09, 09:20 PM
I did my H/G in the car, and all I had to do was remove the timing cover bolts. The cover will slide back enough to get in there and retract the tensioners. I used 2 of those orange handled picks that you find at the discount tool place, and I custom bent them to fit in there just right. If I remember, I used a long craftsman screwdriver stuck down though the opening in the head where the chain comes through to push the shoe back while the pick was holding the release lever. While they are retracted, slide the cam gears on the cams. When the engine is at TDC on #1, the marks are exactly 90 degrees perpendicular to the head surface. To double check, after I installed the chains I turned the engine over by hand a few times to make sure the marks were lined up right. Then I spun it with the starter to check the cranking compression. If I was off a tooth, the cranking compression should be off on one bank.

I tip my hat to you for your ingenuity and creativity to do this project that way and get it to work. Good job!

zonie77
11-12-09, 09:25 PM
Bigtone,

Did you ever write up some of the things that are unique to doing HG's in the car? It's hard to search for a tip like you just gave.

bigtone
11-13-09, 05:00 PM
Thank you for the compliment. I did start a thread after I finished the job.

http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/160216-hg-timesert-car.html

See if that works. I placed a few pics on there too.

Next, I have to replace the intake plenum on my wife's 01 Deville. Should be a piece of cake after doing the H/G job. My son also has an 01 Deville. Oddly, it is the exact same color, interior and options as my wife's. Needless to say, most of my neighbors wonder about me......

zonie77
11-14-09, 12:21 PM
I forgot about that! LOL

You put a good title on it, search should find it.

mikelawson
11-19-09, 02:35 PM
I use a small allen wrench to hold the tensioners retracted, works perfect.

tateos
11-20-09, 02:35 PM
I used the paper clip, like they tell you to do in the chassis manual