TheSamba.com :: View topic - Street cleaner dodgin' head gaskets and valves on an '83.5

Fri Nov 11, 2016 8:25 pm

After a hardy push west up Lee Vining just past Mono Lake left the van overheating, I spent a week in Groveland just outside Yosemite getting intimate with the joys of frail aluminum thermostat housings and water pump replacements.

The remainder of the drive to San Francisco went smoothly, until the engine cut out on the freeway and I proceeded, recklessly, to drive a bucking van to a place I could park it for a little while. Fuel pump, I figured. But when replacing that didn't work, I tried a compression test before throwing any more money at parts.

Cylinder #1: 160psi
Cylinder #2: 155psi
Cylinder #3: 30psi
Cylinder #4: 155psi

Ah.
So the head is coming off. Whether the damage was caused by the overheating back in Yosemite, the continued driving on a potentially fuel-starved engine, or some other undetermined cause is a mystery yet to be solved.

Housing situation is up in the air - so trying to get all this done with the car parked in the street. Fluids are drained and I'll be chippin' away at this for the next few weeks while I look to get settled back into the city.

Any advice, feedback is appreciated! I've gotten a great deal out of this site, figure'd I'd try and share a bit more now that I'm getting into the engine.

Hopefully this will end with a picture at the coast, and not a craigslist ad.
Lookin' forward to it.

Thu Nov 17, 2016 1:54 am

This is my 1.9.

I am becoming very familiar with the peculiar habit old bolts seem to have when someone attempts to separate them from old aluminum.
(The habit is that they break)

Air intake came off easily enough.

Note the oil residue inside. Thoughts are welcome. I will look into this further.

Exhaust removal:
Undid the connections to the head itself, and though this junction here gave trouble, some WD-40 did the trick.

We're off.

Didn't have to support the engine and remove the engine mount - it's a bit of a puzzle but it comes out. Left muffler in.

Learned a bit of a trick to get the remaining exhaust bolts off. The chewed up bolts kept slipping in my vice grips, but leaving them open and letting the tool wedge itself between the bolt and the pipes gave the friction needed to get the bolts off.

Removed bolts.

Cut the old water jacket to be sure I wasn't pulling the cylinders out with the head.

Using a flathead screwdriver I applied pressure to the tabs labeled here:

I had to do a bit of this from both the top and bottom, but that separated the cylinders.

Pushrods out.

Removed shield to remove head.

Here's what we're working with. Not too pitted, but I think these have been off before - it looks like there's some JB-Weld type material up top.

Piston #3

Piston #4

Cylinder #3

Cylinder #4 - I might just have a crack in there.

So now, a few questions. Frankly, I expected to see a valve burnt out, or something more obvious - I'm new to this.

1.) Is it possible to be losing so much pressure (#3 had 30psi while the rest had 155-160psi) through the sealing surface of the valves, or does the fact they appear intact mean my piston rings are shot? I didn't do a leak down because I lacked compressed air, but now my diagnosis is a bit trickier. Still had cross-hatching on the insides of both cylinders.

2.) Piston #3 looks a bit rough - dents and the like. How's it look to a more experienced eye?

Any input is hugely appreciated - I'll be heading back this week to clean things up a bit and see if I find anything else.

Thu Nov 17, 2016 3:28 am

The head is off, the rockers are off so all four valves are fully closed and sealing.
But are they sealing?

How to find out in a low tech way?

Pour a little gasoline into each head port.

If the valves are seating, gas will not seep out.

Not seating well?

The gasoline will tell you quickly.

Too late fir any practical ring diagnosis now with the head off.

Dave

Thu Nov 17, 2016 5:39 am

Good start - keep at it.

PS/FWIW: WD-40 is not penetrating oil, unless you mean "WD-40 brand" PENETRANT... :roll:

Anyway, lots better options - this chart is often quoted but still relevant:
Quote: Pentrating oil / torque load / Price per fluid ounce
no oil...............516 ft/lb.......free
WD-40.............238 ft/lb.......25¢
PB Blaster.........214 ft/lb.......35¢
Liquid Wrench...127 ft/lb.......21¢
Kano "Kroil"......106 ft/lb.......75¢
ATF-Acetone mix.53 ft/lb.......10¢

The ATF-Acetone mix was mixed 1 to 1 ratio.

Thu Nov 17, 2016 9:41 am

call ken at jansen enterprises in Belmont just south of san fran. he should be able to get your heads fixed, valves done etc... or at least be able to give you bad news (ie head no economically repairable) he is a good vw rebuilder, done several engines for me and friends, aircooled and wasser boxer reasonably priced too.

good luck

ps consider getting your van towed to his shop, he may even let you do some of the re assembly work there to save some money. sure beats working on the street!

Thu Nov 17, 2016 9:57 am

Although I cannot provide any mechanical help what I can provide is some encouragement :). Good work taking this on, I tip my hat to you sir (especially doing it on the street!). Keep it up and keep us posted; I'm interested to see what you find.

Thu Nov 17, 2016 10:09 am

Not sure where you are parked now but if you need some tools and such please hit me up - I'm in East bay

Thu Nov 17, 2016 11:55 am

I would have a hard time going that far into an engine and not replacing the rings while I was there. This would also allow you to see the piston skirts to check for wear and damage there.

Thu Nov 17, 2016 1:18 pm

I too was curious of marks at piston 3

Would a really low compression reading on only one cylinder be the only cause of the engine 'cutting out' and bucking?

Not doubting what the OP has said, just looking toward helping with diagnosis.

Neil.

Thu Nov 17, 2016 1:35 pm

Vanagon Nut wrote: I too was curious of marks at piston 3

Would a really low compression reading on only one cylinder be the only cause of the engine 'cutting out' and bucking?

Not doubting what the OP has said, just looking toward helping with diagnosis.

Neil. t

my van prior to rebuild have really low compression on one cylinder much like the one in this post, ran fine, a little bit low on power but ran fine.

Id also be interested in what the oil pressure was like prior to this motor coming apart. if the pressure was low, either the pump is going bad, or worse, the bearings worn out. hence the importance of diagnostics prior to engine dissassembly.

How many miles on this motor? if the bottom end has 200K miles, id be thinking a full rebuild would be prudent. but budget and time may not allow that, still I wish the owner wohld have asked before pulling it apart. leason to learn is take your time, do research before pulling something apart.

good luck

Thu Nov 17, 2016 8:47 pm

bluebus86 wrote: still I wish the owner wohld have asked before pulling it apart.

Well, he sorta did on the 11th...

Thu Nov 17, 2016 9:37 pm

WLD*WSTY wrote: bluebus86 wrote: still I wish the owner wohld have asked before pulling it apart.

Well, he sorta did on the 11th...

yeah sort of, but he also had already drained the fluids, so running the van for a leak down (warm motor) and oil pressure test were already out the window. live and learn, hopefully this will work for him, the head repair.

for the original poster.... who will be doing the head work? do you have a shop lined up yet?

how many miles on the case?

Fri Nov 18, 2016 3:50 am

djkeev- Thanks for the tip, I'll try the gasoline in the head ports.
dhaavers - Hadn't seen that chart before, thank you!
Vanagon Nut - I don't think the low compression was the cause of the bucking, though I'd worried it'd been a result of whatever was creating that problem.
bluebus86 - Thanks for all the feedback - oil pressure as far as the idiot light goes was ok, and that sensor is new - but we'll see. I don't have anybody lined up for the head just yet - may just try and get it down to Ken. Block has at most 170k on it, with a vague rebuild of an unknown extent somewhere in its past.
Here's a more thorough rundown of events leading up to this:

1. Overheated.
Overheated on pass - shut off engine and pulled over immediately. Bled coolant, checked for leaks, soldiered on. Overheated on pass - shut off engine and pulled over immediately. Leaking coolant from reservoir. Let cool. Bled coolant. Vowed to pull over immediately once needle reached halfway. Made it up the pass in 5 minute intervals. Coolant stayed sufficiently cool (both by the gauge, and at the rear) At this point, I figured it must just be one hell of a grade. Made it to the top, entered Yosemite Park. Light came on going downhill. Pulled over immediately. Leaking coolant from reservoir. Radiator cool to touch. Considered a bad thermostat. I was confused by the ability of coolant to bleed out of the radiator at high RPM, though I now understand the thermostat blocks the return flow, allowing coolant to reach the bleeder valve regardless of thermostat functioning. It was getting dark, so we camped. Still convinced it could be air in the system, bled once more and decided to continue and try to get to the mechanics in Yosemite Valley. Driving in 5 minute intervals and coasting on downhills kept engine relatively cool - made it to gas station where we used a payphone to call the tow. Noticed a more steady drip from the water pump.

Tow truck driver pinpoints water pump leakage to weep hole - diagnoses bad water pump. We drop the van off with friends in Groveland.

2. Replaced thermostat and water pump, and reattached muffler which had been half detached for some time.
Parts not available any time soon, I catch a ride with a friend to San Francisco, do some reading, and buy a pump, gaskets, and thermostat. Return to Groveland, replace all parts, test old thermostat - it's no good. Figure pump may have been good to start, but damaged by overheating. Get the car started, and at the same time tighten the bolts attaching the muffler to the cat as they had been incredibly loose and making a racket for some time.

3. Car cuts out at lower RPMs, still drives well and avoided by changing driving habits.
I go for a test drive, it's smooth. A while into the drive, notice that at lower RPMs the engine starts to kind of.. putter. Not quite cut out, but fight me a bit. Clutch in returned things to normal. I mention the muffler reattachment because my first thought was maybe some back pressure - that maybe it'd blown loose from being clogged. I also figured I was just letting the RPMs drop too low, and that my driving habits were to blame - applying the second theory seemed to fix the problem, so I pushed it to the back of my mind.

4. Drive 3-4 hours to SF no problems. Car dies on freeway. Bucking begins. We drive off freeway. Parked, car starts and runs but dies shortly after.
Drive 3-4 hours to San Francisco with no problems. Make it past Daly City when I look down and notice my van is off. Pull off highway. Restart van. It dies. Restart van. Revs keep it alive. Drive off highway to safe area balancing clutch and accelerator to keep engine running. This is where the bucking I describe really begins. Parked, we try and diagnose. Gas gauge shows a quarter, but I throw 2 gallons from a reserve tank in just to be sure. Car starts, then dies. 5-6 miles from our destination and with no specific place to tow it, we start throwing parts at it. Fuel filter? No luck. Remove air filter, and this keeps the engine running - so we put in a new air filter. Loosen the muffler again in case that's contributing. At this point, my memory is a bit fuzzy - either it ran with the new filter, and I replaced the spark plug wires with some that I had in the car just for good measure, or it died again, and I tried the new wires in an attempt to resolve the problem - I'm leaning towards the second.

We drive onwards to the general neighborhood we're shooting for, and the motor continues its habit of dying, bucking, until I get to a spot I can park it. Some symptoms had hinted of a fuel pump issue.

5. Tried:
Gas - No luck
Fuel Filter - No luck
Air Filter - Initially, some luck - but ultimately no luck.
Spark Plug Wires of Potentially Questionable Quality - No luck.
Spark Plugs - No luck.
Week goes by.
Fuel Pump - At first, engine cranks but doesn't start. After fiddling with spark plugs and wires, starts, but is running poorly.

And here we are.
Obviously, I'm learning a lot from my mistakes here - namely I aught to be more methodical in my replacing of parts to diagnose an issue so I'm not introducing all these new variables. That said, I tested my compression before going more in depth into fuel system/spark testing and the low compression seemed like such a red flag I figured that had to be addressed before moving forward - I should have checked in here first.

Much thanks for all the support, advice, and commentary - it's all very appreciated! Here to learn - I welcome any theories.

And a quick question - is it at all possible/advisable to replace the rings without removing the engine?

Fri Nov 18, 2016 10:07 am

Could be several things at play here but it sure sounds like you're being methodical now and obviously reading up on potential issues. If you suspect a clogged exhaust, maybe disconnect cat at muffler inlet, slide muffler away and have a look inside cat.

From what I've recently learned, it's best to get the cylinders measured then decide if they're worth honing or at least deglazing. i.e. just putting in new rings would be a waste of new rings. Given the compression results, you are most likely looking at a head issue or seal between head and cylinder.

My first thought is: search tencentlife posts here on engine building. There are definitely other member posts worth reading. I'm in a hurry so thats the first name I can recall.

Neil.

Fri Nov 18, 2016 10:27 am

tough call. i assume your budget constained, arent we all. i would prefer to do this kind of engine work inside, not in tne street, and with engine on a bench.

the bucking could be an issue with the injection or ignition system, i doubt it was simply from the low compression. but we already crossed that bridge, and the low compression is an issue to deal with.

have you determined if tbe valves are leaky? (djkeevs gasoline test????) if they are leaky, then good, get the head to ken or someone to fix. if no leaks, and no signs of leak at head to cylinder seal (no combustion products in coolant) than the rings may be an issue. if you end up doing the rings, do all four pistons, pull the motor get the other head and valves into shape and at that point it wont be that much more to split the case, see how worn the bearings and cam are, basically youll have a rebuilt motor $$$. then you can diagnois the the injection and ignition system. now the money, do you need new heads? or can they be saved with a simple valve job? are the pistons and cylinders shot, or simply in need of honing and new rings? is cam worn or not? etc........

also consider installing an used running moror?

spark plug wires can be tested with an ohm meter, no need for guess work here, but that is down the road latter

lack of an oil pressure warning dont mean the oil pressure is good. the warning system activates when you have pressure well below the wear limit. Id hate to have ypu put in a new head and or rings, just to find later the oil pressure is marginal. however it is good that you had now alarms during the over heat, as when the engine is supper hots, that is when the oil pressure can be expected to be lowest

again tough call, time and ,money constraints verses long term reliabilty or quick fix to get you another few thousand miles, then repair again.

contact ken (hard to reach on phone, so keep calling or if in a hurry show up, right off 101 at harbor blvd ) and ask him what he thinks, cost estimate etc.... or try other vw builders you need to get some prices and options on the table to make an informed choice on best direction to go.

i recall your head had a repair, like jb weld??? if so, you probably are dealing with former cheapo repairs, bandaids. you had a dinged up piston too, right? so do you really trust the other repairs on this motor for long term reliability? maybe time to bite the bullet and get it rebuilt, but if youcant afford it, then you end up with more bandaids, and low reliability, eventually you end up spending more in bandaid repairs, towing expenses, lost time etc.. than a proper rebuild costs, pay now or pay later. at least in your favor you are able to do some of your own work, and that can save big money.

so call around some shops, get estimates, show them the photos, bring the head, discuss the unknowns, the glued head, the bucking, the dinged pistons, etc... and get a vareity of repair options and estimates.

good luck, work fast, the rainy season is rapidly approaching, it sucks working in the rain outside. rain is predicted this week end :cry:

Thu Dec 08, 2016 5:04 pm

Alright - a few updates.

Pulled the other head, pulled cylinders and removed the pistons.

This round, was able to pull the head quite a ways off prior to removing the cylinders by applying pressure to the tabs at their base.

Used PVC, a bolt, washers, and some nuts to remove the wrist pins.

And we're free!

Took the pistons down to Jansen Enterprises, Ken measured them for me - number #3 was sloppy. 1, 2, and 4 were all the same, but #3 had been swapped out before - I unearthed a GEX sticker around this time as well, so either they blessed us with that piston or a later set of greasy fingers did the deed. Thanks for the tip, bluebus86.

Ken also took a look at my heads - my cracks aren't too deep, so I'm gonna grind the valve seats a bit and hope for the best.

A very kind Vanagon owner let me pull two pistons/cylinders from a 1.9 he had sitting around, gonna measure those today, get new rings on, and hopefully have this thing at least reassembled by mid next week. Have new seals/rings in box.

A question - would it be better to use the old cylinder with the new piston? Or should a piston generally stay with the home its worn into? I suppose measurements will give me an answer there, but thought I'd ask for advice on that subject.

Thu Dec 08, 2016 7:32 pm

Regarding the low compression on Cyl. 3
Have ever done a compression check on the engine before this?

Thinking of long term low compression problem if that source of the low compression is the bit of metal caught between the Cylinder head and the Piston skirt. If this was leaking from the time it was installed there was lower compression on that cylinder which means that there was less thrust acting on the connecting rod and the crankshaft bearing for this cylinder.
If and when you tear down the engine for a complete rebuild I would expect to see abnormal wear on that bearing. The thrust on it was not equal since the opposite cylinder had full thrust acting on it

Now having said that if this was the cause of the low compression I would expect to see more blow-by effect from the escaping gases.
I see some, but not really that much. It doesn't really look like blow-by when you look at the matching engine side.
Any blow-by would be going into the cooling jacket and you did not have high coolant pressure that you know of.

Agree with pulling the other side and doing rings on all 4 cylinders.

Thu Dec 08, 2016 8:12 pm

Looks like you pulled the wrist pin bushing out of its bore on #3. This is not a good thing.

Where are you in the Bay Area?

Fri Dec 09, 2016 2:07 pm

Hey Steve, that bit of metal is - interestingly enough - on cylinder #4. This was the first time I'd done a compression check.

The new-to-me pistons I acquired are in far better shape than any of my old ones, I'm going to try and pull the other 2 this week and swap all four piston/cylinder sets over.

jberger - the car is parked in the lower sunset of San Francisco. That picture shows the wrist pin bushing of #1 and #2, it does look like I pulled #2 out of place there.

Fri Dec 09, 2016 11:54 pm

if things measure within spec, you can reuse them, make sure the cylinders get a nice cross hatch hone pattern on them. ask ken to measure them if you dont have the tools. also pistons are very very delicate percision soft metal parts. please avoid tossing them in a bag with the big heavy sleaves, that is a good way to ding up the piston. instead wrap each one in newspaper and store in a box without heavy tbings like iron cylnders treat the pistons like the percision critical parts tney are. use great care when removing and installing the rings. make sure you do not gouge the soft piston ring groove material in any way, even small scrathes can effect ring sealing, resulting in power losses, oil burning short life etc....

treat the pistons like an expensive swiss watch.
handle with care.
good luck