Chevy & GMC Vans

My '98 has been low on coolant every now and then over the last few years. I would just add a little to the overflow and pretend it wasn't really happening. The other day I noticed a "green" (I switched to green last year) drip on the front diff, oil filter and "bell housing".

I replaced the water pump when I went to green. I'm seeing a little weep on the left rear intake but I'm pretending it's coming from whatever solenoid that is right there. Also dampness above the driver's side water pump flange....

Only 110,000 miles, and a slow leak(s), but I take this thing to some seriously remote locations. So, tear it down????

photo_van wrote:My '98 has been low on coolant every now and then over the last few years. I would just add a little to the overflow and pretend it wasn't really happening. The other day I noticed a "green" (I switched to green last year) drip on the front diff, oil filter and "bell housing".

I replaced the water pump when I went to green. I'm seeing a little weep on the left rear intake but I'm pretending it's coming from whatever solenoid that is right there. Also dampness above the driver's side water pump flange....

Only 110,000 miles, and a slow leak(s), but I take this thing to some seriously remote locations. So, tear it down????

Yes, its not a big overly complicated job and it will give you peace of mind..

Ditto on that.
I did mine a few years ago with just a Haynes manual, not hard, just a PITA to go so deep.
Take your time and do it right, clean everything in that dog house you can and clean and rebuild every part you have out. I regret having not opened up the plenum and replacing the spider and poppets while it was out. One of those "had I known then what I do now" deals.
My truck runs rich and always has. It would have been an easy job on the garage floor.

I've read all I can find on this, got my OEM manual out, got the fancy Fel-pro gasket set. Guess I'll dive into it this week (hopefully it warms back up a bit, snowed last night!! Sunny California?) There was mention of a factory service bulletin regarding the torque on the manifold bolts but I haven't been able to actually find it. Anyone know if it is different then what's in the manual?

Also, Woodbutcher, care to share what you know now that you didn't know then ? I'd like to take care of everything I need to while I'm in there. As far as running rich, I changed my plugs last year and they looked good.

Thanks for any input you all have!!

I think I have a leaky spider or something amiss inside the intake. It would have been an easy job to open up on the bench and replace it all or at least find the issue and effect repair, now that it's back in and running again I'm not to enthused about the idea of digging in again. That poor beast has 260,000 miles on her and runs great. The subframe is rusting, both rockers are shot and the body has loosened up over the years. She still hauls my butt and my gear to work every day so I'll run her till she dies or commits suicide but I won't be opening the plenum until I get a no start situation.
At the time my biggest concern was to not F/up,,, I'd never been into an engine that deep before and couldn't afford mistakes. I knew very little about how the intake worked, I'm not a mechanic and can't afford one. Since that time I joined this and the other forum and have learned a thing or two, one being if your in there anyway, fix it.

Wow, 260,000. At 10,000 a year I'll be a pretty old man by the time mine gets there!

Well I had a couple of hours this morning before having to go off to a music festival. Got most all the preliminaries striped off the thing: shrouds, alternator, cables and wiring harness, A/C compressor is loose. I can see something no one seemed to mention being a bit of a pain. Rear A/C has the extra line that isn't going to allow for moving the compressor and lines out of the way. I may have to split the manifold to get it out ](*,) Maybe see tomorrow.

waiting for the ice to melt off the van this morning

I found this guys site on youtube. A lot of Astro stuff, probably should be stickyed somewhere. http://www.youtube.com/user/ScottysDetailing/videos

Got it all torn down today. Managed to get it out in one piece. Happy to see only two small gasket cracks to the outside. The heads look great with no pitting. One of the water gallies was rather gummed up with a jelloy rust.

Challenging to clean all the built up sand/oil grut without it ending up down in the valley or worse. I've got it all sealed with paper and rags but I still don't trust it. Ended up using my shop-vac in tandum with a scraper, worked pretty good.

Unfortunately a tack sized sand/grease glob ended up down #3 intake as I was removing the manifold #-o

Any point in looking inside the upper manifold? I have the gasket.

Thanks

I removed the upper and cleaned it also. It was full of some gunky residue. Yes..."gunky" is a word. I just made it up.

Yepper, that's what I was talking about. You have it on the bench, gasket in hand, and you really have to ask?

If for no other reason but to clean, yes.

Got it mostly together yesterday before the next storm blew in. 40 mph winds today, maybe a good day under the dog house working on installing the distributor and a few more odds and ends. Like you all said, not a difficult job as much a tedious one.

New valve cover gaskets and CLEAN valve covers! Ditto the plenum, though on the inside it ended up only semi clean, as the carbon varnish just seemed to be endless. I was tempted to replace the "spider" but figured at a few hundred $ "why fix it if it 'aint broke". Replace both breather hoses as they were dissolving.

As much as I lamented redoing a bunch of work I did last year, I found an issue that I created when I replaced the alternator: I apparently had trapped the wiring harness between the alt and the valve cover and it had worn through the corrugated plastic, tape wrap and was rubbing on the wire insulation. Could have been a bummer!

One thing that wasn't really emphasized much is the fact that (at least on mine) the A/C bracket doesn't just "slide forward" after removing the nut and three bolts. There is some sort of hidden "hang bracket" that I can't even see let alone get a wrench on. I had to use a pry bar and not just a little force to get the top of the A/C bracket out just far enough to get to that front manifold bolt. Also, I found that a 1/2" socket fit WAY better than my 13mm did on these bolts.

Someone on this forum suggested making a "stud" to help align the manifold; I did that and it worked very well.

With the fan shroud removed, I have a good view of my weeping oil cooler lines. Sure wish I had fixed them when I had the front diff out ](*,)

Thanks for the help, encouragement and previous postings on this forum!

all back together, fired right up! Thing of beauty...

Good stuff, one less thing to worry about.

Awesome!

Nice work!