Another Head Gasket Repair Journey

dcarlo · 05-22-07, 12:14 PM

This is a 97 LC 40th with 114K miles on it. It has been well-maintained and runs strong. Avg 12 mpg on the road, but after a recent coolant flush & tune-up , I was getting 15mpg. 3K miles later, the truck started loosing coolant a little at a time and the mpg dropped to 10.

The bubble test showed signs of bubbles... so I took this as an early warning sign... and it was time to call CDan for parts, ordered the DVD from Doug , and got setup for the HG PM.
Previous work has included new brakes, rotors, water pump, starter, hoses, dist cap, wires.

Disassembly was pretty non eventfull (after viewing Dougs DVD a million times, and re-reading the FSM a billion times), I soaked EVERYTHING I could see with PB blaster for a couple of days prior.... and everything came off without incident.

I choose to remove the air cleaner, which provided my small frame with plenty of room to park my butt for hours on end.

I did not remove the wire harness, and choose Dougs recommendation.

The timing chain was a little tricky but managed to get a tie arround the slipper and pinch the chain, so removing the sprocket and subsequent head was not a problem.

I have to admit, getting the top intake manifold off was pretty tricky... getting those bolts from under the vehicle was some serious spelunking!

I had issues with the exh cam which I describe below with pictures.

I was able to pull the head off by myself, was'nt that heavy... I placed a piece of plywood over part of the hood, so I just lifted the head and plopped it on the plywood.... make sure any wood or pressure does not come in contact with the top of the radiator! I have already busted my fan shroud which was an 80 dollar mistake..:-)

I basically have 2 issues at this point.

First,
the number 6 piston is perfectly clean with no signs of carbon !!! (see pics) ... what the heck ? Was I running on 5 cylinders all this time ? The valves on the #6 were all black. Something was running very cold here ? any ideas... see pics.

Second,
issue is the Exh cam related to the service bolt. First, I screwed up the 25/35 degree thing and used the wrong holes (single hole instead of the 2-hole mark... i know...

)... although the cams were removed correctly and seemed to come up even. I hope I did'nt cause irrepreble harm. Second, I did not install the service bolt, and the cam came off without incident with the gears alligned...
I know... I have to work on my patience. see pics below.

I'm realizing now (after viewing some of the FSM pics on the dismantle of the cam) that there is a spring (aka ring) that must be providing some resistence to the sub gear? Anyway, from the pics below, you can see that one of the holes in the sub gear is not alligned with the cooresponding hole in the main gear. I assume I will have to get that service bolt in there some how to either release pressure? or relieve pressure? I would appreciate a better explanation on how this sub gear/main gear works... seems like a strange design to me. (note: My truck has always had a slight ticking sound at low idle). Perhaps the cam spring is not working correctly ?
Anyway, I would appreciate enlightenment in this area!

Ok , that's it for now... the injectors are off to RC engineering and I'm looking around Berkeley California for a reputable machine shop for the head.

THANKS!! What an AWESOME forum !!!

--don

Wilkinson · 05-22-07, 12:21 PM

#6 piston is clean because the leaking coolant acted like steam cleaning to remove all carbon. You now know where you were leaking.

dcarlo · 05-22-07, 12:51 PM

Thanks !... guess that explains it.
--don

e9999 · 05-22-07, 02:22 PM

sorry to read about the problems.
but looks like you're doing good.

any enlarged pics of the gasket where it failed?

landtank · 05-22-07, 02:41 PM

you'll need to rotate those gears and get that service bolt in before reassembling. There needs to be tension between the two to provide the zero backlash that was intended.

stevezero · 05-22-07, 03:15 PM

you might as well replace the plug wires too while youre in there. That would eliminate any chance that the plug wire was off/broken... a long shot, but heck, in for a penny, in for a pound.

Good job so far. If it wasnt for those moments of excitement, ownin a cruiser would be boredom......

Rookie2 · 05-22-07, 04:08 PM

Unless it's the angle of the picture, that distortion around #6 looks like one of the worst I seen.

Just curious, did you remove the hood?

Rookie2

IdahoDoug · 05-22-07, 04:40 PM

On the exhaust camshaft gear - how far off is the threaded hole which is supposed to have a service bolt in it? Is it just a bit so you can still see through it, or did the two parts of the gear rotate as much as an entire tooth? Estimate the amount of rotation that happened as a percent of the distance between the teeth.

DougM

dcarlo · 05-22-07, 05:29 PM

Thanks for the support and interest guys!

I will get more pics tonight....

Landtank, thanks, I think I get it now...just curious... is it easy to tell if the camshaft is broken? or does it take analysis at the machine shop? The reason I'm asking, is that I heard a click sound when removing the exh cam, and just thought this was some pressure being released from caps?...

Rookie2, yes the hood is off. And yes, the gasket is quite distorted, the fire ring goes all over the place, like a winding road! I will take closeups tonight to get a better analysis of the actual failure.

Doug (Very nice DVD btw) , in the middle cam gear picture, the bottom hole (the one with 2 holes next to each other), you can actually see a tiny bit of the main cam gear hole towards the left within the sub gear hole. I would say that the hole is off by 20 percent, in other words, I would have to rotate about 80 percent of the width of the hole to get it alligned. I'm going to guess perhaps a full tooth position of rotation. Right now I'm not sure which hole has threads, cuz I'm not in front of it, but I will report back tonight....

thanks again,
--don

landtank · 05-22-07, 06:05 PM

those gears are spring loaded, the click was the gear releasing from that tension when lifted out.

Just get the bolt back in there with the teeth lined up and you're golden.

dcarlo · 05-22-07, 09:42 PM

Service bolt is in !...

Picture shows the service bolt in... it's actually the reflection at the 2 oclock position.

I think i'm an expert with service bolts now.

More pics.... check out the head gasket... is this one for the record books? or just typical? .... I'm glad I got to this when I did, just returned from a 3K mile trip a month ago. What I like about these trucks, is they seem to let you know when things are about to go wrong.... if you listen.

I'll keep you posted on my progress...

thanks !!
--don

dcarlo · 05-22-07, 09:46 PM

Here is a better pic of head.. problem with upload it seams.

e9999 · 05-22-07, 09:48 PM

that is a doozy!

congrats for avoiding sudden death syndrome.... good eye!

MoGas · 05-22-07, 09:54 PM

I'd say thats blowed alright

knorrena · 05-22-07, 11:18 PM

Glad to hear that you got the service bolt thing worked out. Tell me about the front bumper you have?

Karl

dcarlo · 05-23-07, 12:15 AM

Bumper is TJM-T17. I wanted a clean bumper with no bull bar that would accept a winch. This will accept a 9000lb low profile winch hidden behind the bumper. Got it from Slee.

http://www.sleeoffroad.com/products/..._t17_front.htm

cruiserdan · 05-23-07, 08:27 PM

Quote:

Originally Posted by dcarlo

Here is a better pic of head.. problem with upload it seams.

I want that old gasket.

Please send it to me.

dcarlo · 05-23-07, 09:27 PM

Done. I'll be extra carefull not to destroy it when I remove it.

MoGas · 05-23-07, 10:23 PM

Quote:

Originally Posted by cruiserdan

I want that old gasket.

Please send it to me.

Is this the worst blown?

cruiserdan · 05-23-07, 10:26 PM

Not really.

I'm just trying to aquire every failed gasket I can get my hands on.

e9999 · 05-24-07, 08:01 AM

Quote:

Originally Posted by cruiserdan

Not really.

I'm just trying to aquire every failed gasket I can get my hands on.

oh yea! please count me in for the class-action lawsuit for the free engine...!

dcarlo · 05-24-07, 10:45 AM

I hope I can get more than 114K on the newly designed HG.... definitely the weakest link in an otherwise tremendous truck.

Are there definitive suggestions on how to care for my new HG baby? should I read to it every night? sing it songs ? cuddle it ? ... Or is just going to mis-behave again like all the other HGs? ..:-)

--don

DuManchu · 05-24-07, 11:06 AM

Holy shnikes that thing is blown.

Don't forget to have the head checked for warpage. (If it hasn't been mentioned already, I kinda skimmed through)

EricE · 05-24-07, 12:56 PM

Quote:

Originally Posted by DuManchu

Holy shnikes that thing is blown.

Mine was blown worse than that (done a couple of weeks ago). Mine was blown in the center back of #6. Of course, it would have lasted more than 40K if they had installed it correctly. 1/4" of the HG was sticking outside the engine.

turbocruiser · 05-24-07, 10:38 PM

Quote:

Originally Posted by cruiserdan

Not really.

I'm just trying to aquire every failed gasket I can get my hands on.

Uhhh, why? You 'fraid some forensic test will reveal the voodoo pin penetrations!?!

landtank · 05-25-07, 08:55 AM

Quote:

Originally Posted by turbocruiser

the voodoo pin penetrations!?!

Is that what Mrs. CruiserDan is calling it now?

dcarlo · 05-25-07, 10:03 PM

Head results from the machine shop....

No Warpage.. head is in good shape. Most valves are leaking however.... so I went ahead and let them do the valve work and shave the head. They are highly recommended local machine shop... so the head should be as good as new with all new perfectly, adjusted ,tight valves!

Can't wait to start putting her back together.... hope I can still read my disassembly notes...:-( ... I have a feeling I will be asking "Uh ... where does this go?" questions sometime soon....

--don

akcruzers · 05-25-07, 11:34 PM

Can't wait to start putting her back together.... hope I can still read my disassembly notes...:-( ... I have a feeling I will be asking "Uh ... where does this go?" questions sometime soon....

--don[/QUOTE]

Don,
Do yourself a favor and get the apropriate thread chaser or tap and clean out ALL of the head bolt threads in the block. Clean all old gasket residue with sandpaper or polishing disk. Dont forget to use a good synthetic oil (I use ARP assembly lube) on the threads when torquing the head bolts to spec.

Good luck,
AKCRUZERS

dcarlo · 05-26-07, 07:49 PM

Thanks , will do. What exactly is "Thread chaser" ? ... and how would I tap the threads?
BTW... nice pics on your web site... :-)

--don

beno · 05-26-07, 09:18 PM

Quote:

Originally Posted by dcarlo

Thanks , will do. What exactly is "Thread chaser" ? ... and how would I tap the threads?
BTW... nice pics on your web site... :-)

--don

Get the correct size (thread) tap and just go in and out of the 14 head bolts to get any grease, rust particles, gunk, etc. out of them before you put the new head bolts back in.