refurbishing headers on 1.9l

beachinwesty · Posted: Sat Mar 17, 2012 7:14 pm Post subject: refurbishing headers on 1.9l

ok, here are the details.

1985 automatic weekender with stock 1.9l.

Lots of tiny bubbles in the expansion tank when engine is hot and lately it started stalling when warmed up and I came to a stop stop lights and whatnot. I was thinking maybe the metal cylinder o-ring or the green rubber ring had gone bad.

My VW mechanic looked it over. Low compression in two cylinders, and his conclusion was that it was most likely a problem with the exhaust valves. His bet was on stretched valve stem. He checked all of the usual suspects (oxy sensor for ex among others) and could not think of any other cause.

Today I prayed to St. Patrick and pulled the cylinder heads on both sides. I didn't have my camera with me today but will post photos of the pistons and heads later this week.

#4 piston was gunked up with heavy black deposits but wasn't oily (none came off on my finger) and the spark plug wasn't fouled, but the plug didn't have the same grey carbonized look of the other plugs.

#2 piston was perfect, no varnish or anything.

#1 piston had varnish, not too much, and #3 piston was the same.

Heads looked ok, but exhaust on #4 was black, while all the others were ash grey. Too tired by the end of the day to check them closely.

Had no problem with cylinders being stuck in the head and the job actually went really smoothly.

Best money I ever spent was to pay the mechanic to put new exhaust pipes on while he had it in the garage. I would probably still be out there working if I had to pull the old rusted pieces off myself.

Next step is machine shop for the heads and place a parts order for coolant hoses, fuel lines, gasket kit. I'll have my mechanic take a look at the heads to determine if the exhaust valves really are the problem and we'll go from there. Desmond's Auto in B'more is a great place for your van and their advice has been invaluable.

I'll post more as I progress. I can't believe I actually did this. Maybe I'm actually going to pull this off.

ftp2leta · Posted: Sun Mar 18, 2012 4:47 am Post subject:

I have never seen a valve problem on a water cool engine (stock head), never in over 65 engine. So let's say that valve should not be the problem.

You have a case of a badly sealed engine, nothing else.

Since your there check the top piston ring, I have seen quite a few broken one.

How was your oil consumption ? Good! leave the piston alone, change rings as a precaution.

Head, ANY sign of crack between valve/spark plug.... garbage. AMC heads with German exhaust valve is the way to go. If your on a budget, find some decent used heads.

Ben
_________________
Working with rust, grease, dirt and dust is a sad truth.
------------------------------------------------------
FI part for sale: http://www.benplace.com/parts_sale1.htm
My site: http://www.benplace.com/vw2.htm
Subi conversion: http://www.benplace.com/vanaru_eng.htm
Youtube http://www.youtube.com/user/ftp2leta

beachinwesty · Posted: Sun Mar 18, 2012 6:43 am Post subject:

Thanks for the input about the exhaust valves. I will have them checked before I continue down that road. If the problem is that the engine seals were failing, I worry because I'm not sure I can do a better job. I'm suspicious of the a fix being as easy as just opening up the engine and resealing everything. Can it really be as simple as that?

It has never consumed any oil, so I don't think the piston rings have any problems. You suggested that I change the top piston ring, but I don't see how I could change the top piston ring with the engine in van right now.

I'm not sure how to get the varnish off of the pistons. Any thoughts here would be helpful.

beachinwesty

Took the heads to the machine shop today. I'll have more details after they inspect, but in the meantime, here a photos of the heads and the pistons.

Image may have been reduced in size. Click image to view fullscreen.

beachinwesty · Posted: Wed Mar 28, 2012 11:07 am Post subject:

So I decided to replace the piston rings as well. Taking the cylinders to the machine shop today and parts are arriving in the mail. I'll be putting everything back together next week.

I think what happened with the van was there was a leak between the cylinder o-ring and the head on cylinder #4. That was causing the bubbles in the coolant tank that I was seeing, causing the low compression and causing the van to stall once the leak became large enough.

MarkWard · Posted: Wed Mar 28, 2012 11:14 am Post subject:

Coolant leaking into a cylinder can clean the heck out of a piston. Old timers would seap water into a running engine through a vacumn port to decarbon it. I do not recommend this, but offer as an explanation as to why the piston would be carbon free.

Yes, resealing could be as simple as taking it partially apart and reassembly. The trick is in the tiny details that might get missed by someone with less wbx engine building experience. I don't think you can make it worse than it was and hopefully it will come out better.

beachinwesty · Posted: Fri Mar 30, 2012 4:36 am Post subject:

ordered the empi 94mm piston ring compressor yesterday. Expect to have heads and cylinders back on Monday to begin putting everything back together.

Monday - fitting new hoses for coolant and fuel, mounting the new oil cooler and cleaning the pistons and piston ring channels.

Tuesday - cylinder reinstall day and maybe head install as well, depending on how well the cylinders go back on.

Wednesday - finish head install and mount everything that was removed

Thursday - finish oil cooler install and fire up possibly

Friday - fire her up for sure

beachinwesty · Posted: Thu Apr 05, 2012 6:06 pm Post subject:

Wow, what a week. Took me 30 minutes to put the cylinders back on the #2 and #4 pistons (back of engine). The other two pistons are another story.

I was using the EMPI 88-94 mm piston ring compressor and it was really hard to hold the tabs together with one cylinder already installed. There is very little space. So I used a file and cut a notch into both tabs of the compressor. That allowed me to take a small bolt with two nuts, one at the head and the other at the end, and insert it into the notches after I compressed the ring with pliers. This held the piston compressor together and I could tighten it just right without having to hold it. This worked great. I'll upload a photo tomorrow.

Even with the piston rings compressed really well, the jug and the piston kept going akimbo as I tried to gently hammer the cylinder onto the piston. The piston would jam and clearing it would cause the compressor to skew out of alignment and a ring would pop out. Frustating and exhausting. The solution was simply to get a helper to hold the cylinder straight while I tapped with the mallet. That worked great, and both cylinders went in without too much trouble.

Heads went on great but couldn't install the coolant hose between the thermostat housing and the driver's side head. I need to remove the water pump and install the small hose to the head. That's tomorrow's job.

The heads are on and the job is almost done!

beachinwesty · Posted: Tue Apr 17, 2012 11:42 am Post subject:

well, I managed to shear a bolt off of the thermostat housing while scheming to get the coolant hose on. Now I have a leak from the bolt hole. Have to pull the water pump and have the bolt extracted and a new one inserted.

tried to start the van yesterday, leak or no leak. Engine would turn over but did not feel it trying to catch. I think I have no spark. Will troubleshoot this next time.

Also, where should the distributor be pointing when the main pulley notch is at 12 o'clock? That's TDC for the #1 cylinder right? It seems like it should be pointing right at the #1 wire. Please correct me if I'm wrong.

Thanks

MarkWard · Posted: Tue Apr 17, 2012 12:42 pm Post subject:

Remember on a 4 stroke engine, you have TDC twice. In answer to your question, yes, with the crankshaft at TDC for cylinder 1 not cylinder 4, the rotor should be pointing near close to where the #1 sparkplug wire is connected to the cap.

beachinwesty · Posted: Tue Apr 17, 2012 12:53 pm Post subject:

ok, I thanks. that helps.

tencentlife · Posted: Tue Apr 17, 2012 6:04 pm Post subject:

The map is not the territory, true, but a guy oughta at least have the right map:

____________Flywheel____________

3_____________________________1

4_____________________________2
______3____2
________diz
______4____1
_____________Pulley_______

crankshaft and diz both rotate clockwise

Flail on!!
_________________
Shop for unique and useful Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/
also available at VanCafe.com!

Please don't PM here, I will not reply.

beachinwesty · Posted: Wed Apr 18, 2012 9:02 am Post subject:

Thank you for setting me straight on that. The diagram is perfect to make sure I have it correct.

Ahwahnee · Posted: Wed Apr 18, 2012 10:30 am Post subject:

Sounds like you're clear on it... but FWIW the distributor usually has a scribe mark on the rim (cap off) that conicides with the rotor when #1 is TDC.

beachinwesty · Posted: Wed Apr 18, 2012 5:46 pm Post subject:

today I pulled off the coolant hoses and pulled the water pump/thermostat housing. I accidentally sheared off a bolt on the thermostat housing and coolant was leaking from the bolt hole after refill. No problemo. Everything came off easy and I actually knew what I was doing.

Going to have the bolt drilled out and replaced. Then it's back together and I'll work on getting the van started.

this has been an amazing experience so far. My confidence is way up. I have confidence that I'll have it restarted soon and it will be a good runner. I have worked so hard, but I could not have gotten as far as I have without the helpful VW shop (thanks Desmond's!), a helpful friend with some vw experience, my friends on fullmoonbusclub.com, the kind folks at van cafe who sent me extra stuff, and my friends on thesamba.com.

not done yet, but I have confidence in the outcome.

beachinwesty · Posted: Wed Apr 18, 2012 6:00 pm Post subject:

Here are the photos of the empi piston ring compressor that I modified to make it easier to work solo. Next time I'll pull the engine to do something like this. The quality will be higher and the job easier. I just didn't have the facilities to pull the engine where I am.

beachinwesty

Still hunting down water leak gremlins. Latest one is on thermostat housing. Not a big deal, I've gotten very good at taking the coolant pipes off.

Here's what I did today to try and start the van.

adjusted valves to zero lash and then eased off the adjusting screw 1 1/2 turns per my mechanic's instructions.

checked spark - yes, there is spark

fuel pump is buzzing and working and added a fresh gallon of fuel to the tank.

checked the distributor to make sure that it was passing the #1 cylinder when the notch of the flywheel aligns with the engine case.

Van is turning over but the spark is not igniting the fuel.

I checked that the wires were properly grounded on the engine block where they had been removed earlier in the rebuild.

Oxygen sensor is properly wired, temp sensors properly wired.

Any thoughts as to why no start? Very puzzled.

I'll be getting a compression gauge from my FLAPS this weekend to check the cylinder compression.

morymob · Posted: Sat Apr 28, 2012 4:56 am Post subject:

A bit late in the game now but u didn't mention if the cyls were honed while out???

beachinwesty · Posted: Sun Apr 29, 2012 4:44 pm Post subject:

Yes, I had the cylinders honed while I had them out, and also replaced piston rings.

Today I worked on trying to adjust the valves correctly and made some progress on that, but not enough.

I got a compression tester from my FLAPS and the #3 and #4 cylinder came out at 90 and the #1 and #2 tested low 50-60 and then tested at 0. I checked the fittings and checked the gauge and still got 0 on every test after the first two. I readjusted the valves to no effect.

I give up. I'm getting it towed to the local vw shop. A man needs to recognize when he's beyond his ability. Maybe once it's running I'll have a chance to become better acquainted with the subtleties of adjusting this engine.

BillM · Posted: Mon Apr 30, 2012 6:17 am Post subject:

You either miss typed or misunderstood Valve adjustment.
After getting it to zero lash your suppose to turn in another
1 1/2 turns not back off.
_________________
Bill M
87 Westy


Hello! Log in or Register \| Help \| Donate \| Premium Membership \| Buy Shirts	See all banner ads \| Advertise on TheSamba.com

	Forum Index -> Vanagon	All times are Mountain Standard Time/Pacific Daylight Savings Time Page: 1, 2 Next
Page 1 of 2