Clearly I am a crank. I am attached to this Chev van perhaps overmuch. I get regular offers to buy it, it's in good enough shape to merit a full restore which is sort of what I have in mind. I like the way it drives, the sheer space is not bad either.

I had an overheating event several months back, a bit shy of catastrophic, was about 3/4 of the way up on the gauge. I had been struggling with some coolant loss issues. My mechanic put in two new freeze plugs, a new radiator and cap took care of the rest ... I thought.

I'm having phantom coolant loss. No dripping to be seen anywhere but it still goes through about a gallon a month. I was having some whitish smoke at startup. Additionally, power at 60mph+ seems down. My reading has it that along with coolant loss, compression loss at high speed leads to reduced power.

So I'm biting the bullet - I have a good place to do the work and some time. I'm not far into it - I have the exhaust manifold unbolted, the plugs and wires out, yesterday I drained the coolant, planning to take the radiator out to free up some space plus I'm going to put in a new water pump before I button it up.

I've been reading here and there about misdiagnosing the head gasket issue. The white smoke only lasts briefly. Once warm there's none of it - possible indication that the white smoke is not from leaking coolant.

But looking at all of the freshly drained coolant really gives me pause. It's pristine, looks like fresh out of the bottle. Even with regularly adding new stuff seems some of it would show the taint of oil. Another angle however is the notion that this motor could use a new gasket and head job at 200K, I'm at 190K now.

This is a big job. Taking it apart is easy, getting it back together in optimal fashion will be harder. I do not want to be left with a basket case. Complicating matters, I'm housesitting my sister's place on the WA coast, about 30 miles north of Aberdeen, not exactly a teeming metropolis, and 78 miles from Olympia. There is a NAPA auto parts in Ocean Shores 16 miles away.

I should have done more diagnosis. I don't have my pressure tester with me, I can rent one at the Autozone in Aberdeen but even that wouldn't be conclusive. I've read that garages sometimes have a tester to look for hydrocarbons in coolant. That might indicate some cases where there is a gasket leak but the coolant doesn't look robot coffee.

__________________
1986 300SDL, 362K
1984 300D, 138K

Insure the gasket sealing surfaces are undamaged. You may need the heads/block resurfaced (not sanded at home) to insure proper head gasket sealing. Maybe upgrade to MLS gaskets. Just a thought.

__________________
Tony H
W111 280SE 3.5 Coupe
Manual transmission

Past cars:
Porsche 914 2.0
'64 Jaguar XKE Roadster
'57 Oval Window VW
'71 Toyota Hilux Pickup Truck-Dad bought new
'73 Toyota Celica GT

Look for anything that is exceptionally clean in the combustion area e.g., a piston top from steam cleaning, if it does that is probably a leak location. Get the heads checked for flatness and pressure tested by a machine shop.

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer

If you're not doing a valve job at a minimum have the valves leak tested and replace the valve seals. For valves seals I'd use positive lock style that secure themselves to the top of the guide NOT free floating umbrellas. Check the valve guides for excessive wear especially the ones closest to the EGR valve.

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer

I was thinking to use only Scoth-Brite and mineral spirits to clean both surfaces. Part of the disadvantage of living in the boonies, getting the block checked/resurfaced will be really tough.

My plan was to drive the heads for a redo to Lakewood, a small burg on the south end of Tacoma, about 90 milies away. Was the closest I could find. I'm hoping to get an appointment, so I could hang out nearby and take them back the same day. Avoiding a second 180 mile round trip would be nice. I might be dreaming.

__________________
1986 300SDL, 362K
1984 300D, 138K

I was thinking to get the heads renewed to some large extent. Getting them out again will be tough, would prefer to do it once.

I've read that if a cylnder is squeaky clean it's an indication of 'steam cleaning.'

I found the following from 7 Different Ways a Head Gasket Can Fail:

Wishful thinking perhaps. It's just that the coolant loss is real and real annoying. Not only is it an extra $10 a month, I don't like the idea of stupidly releasing those chemicals into the world. And the nice green and clean coolant is a puzzle.

I was debating not going through with the job. OTOH, this could be the next best renewal short of a long block install which would probably cost 3 or 4 times as much.

__________________
1986 300SDL, 362K
1984 300D, 138K

If you know it's history and it has been maintained a long block probably isn't necessary unless you see scoring on the cylinders. I would at 190k replace the timing chain and both gears.

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer

I bought it at 119K from some sort of small dealer, he also sold parts and repairs - he had aquired it from the orginial owners. This was about '07, it was the third Chevy van I had looked at and way superior to the first two. It had deluxe Michelins, 235/75R15s, all in good shape, even the spare was the same tire. I took that as a sign the owners were not stingy with maintenance. I really doubt the dealer guy bought those tires, the selling price was $1500, I suspect those would have easily been $500 to $600.

Good call on the chain and timing sprockets. I found them just now at NAPA for $44.

__________________
1986 300SDL, 362K
1984 300D, 138K

Too ironic...was explaining the "They went for Michelin" indicator to a friend a few hours ago...

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Consider having a balancer sleeve repair kit on hand, they wear grooves. When driving the front seal into the cover pack the back side cavity of the seal with Vaseline if it has a spring. This prevents the spring from jumping out of place. Support the cover well while installing the seal so it doesn't bend or distort. Take a picture of the gear alignment before installing the front cover to prevent second guessing yourself.

Look closely at the back of the intake manifold and the distributor housing there should be a hash mark in each close to being aligned. Those two marks aligned is where the factory set the ignition timing when it rolled of the line.

Check the balancer when #1 is at TDC to be on zero. If it has slipped you may want to replace it or at least remark zero.

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Good advice. I'm going to need to school the hell out of myself on putting that distributor back in correctly. I pulled the distributor twice on a '67 V-4 Saab years ago, not sure how I landed on my feet.

I just spoke with my former shop neighbor, the best welder I've ever met and a good mechanic, he repeated something I've heard before, not sure how true it is. He claims that rebuilt heads on top of an old block might not last long - too much compression for aging rings. I've read of this referred to as an 'old wives tale.' No idea, but I know this engine has pretty good power and oil consumption is not high. If I had more time I guess a long block 5.0 would be the way to go. Might be around $2K total, I might get away with $800 WAG on the current job.

At present acceleration is good but at around 55 mph it gets anemic and there's an odd noise I can barey hear. My thought was compression loss at higher RPMs.

I use about one gallon a month of the pre-mixed anti-freeze (it's getting harder and harder to find distilled water when you want it) - at Home Despot or Walmart those are around $10. My cynical mercenary side says drive it till it drops and then put in the long block.

My other optimistic side says with new heads, gasket, and the other miscellany, incl. water pump I might get another 80K reliable miles.

__________________
1986 300SDL, 362K
1984 300D, 138K

I found this vid on installing the balancer sleeve. I might stick the balancer in the freezer and use the torch as he did as well. NAPA has the kit for $44.

__________________
1986 300SDL, 362K
1984 300D, 138K

I've heard that concern but only seen it happen once, I wouldn't worry about it. In general if the plugs aren't oil fouled, the cylinders look good and it isn't using much oil you should have a good running engine when done. I prefer to do a compression before pulling it apart and read the plugs.

You can save yourself a lot of consternation if you're uncomfortable retiming an engine from scratch by putting #1 at TDC on the compression stroke before pulling it apart, mark the relationship between the distributor body and the intake. Next mark #1 plug wire position on the cap, pull the cap. Mark the position of the rotor, it should be at #1 wire. Loosen the distributor and whilst you raise it out the rotor will turn, put two hashes on the body of the distributor where the rotor then points. When reinstalling start with the distributor housing rotation marks you made lined up, the rotor pointing at the two marks from when it stopped turning on the way out and drop it in. As you drop it in it should end up pointing at #1 again.

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Sounds like good advice.

Here is a screenshot of the kit I found at NAPA. The same part number on my computer did not use cam shaft in the title. But I was thinking that the balancer might be mounted on the camshaft.

__________________
1986 300SDL, 362K
1984 300D, 138K

Balancer is on the crankshaft and that seems pric$$$$ey.

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer