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Posts
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Hello again,
Here’s the
sordid tale.
Friday
morning, I was about fifty miles into my Carlisle journey. A slight
ticking sound started in my engine, most notably when under a slight to
heavy load. Power did not seem to be diminished and the car was still
moving along fine.
After a few
more miles, there was a sudden burst noise, like a hydraulic cylinder
losing all its pressure in one shot. Not explosion or bang. Immediate
loss of power. I pulled onto the shoulder and opened the engine cover.
Lot’s of smoke, no fire.
Headed home
courtesy of AAA and returned for the weekend in one of my Volvos.
Upon
returning home Sunday evening, I started in on the car.
Removed valve
cover, left side of engine. Rear most push-rod (I think
cylinder 4 exhaust?) was out of the rocker arm cup.
Removed
rocker arms. All cups look fine.
Removed
push-rods from intake and exhaust. Ends look fine. No scuff
marks, no mushrooming. Push-rods are straight.
Rear most
valve spring is slightly compressed. It does not look like
it’s broken.
With
everything back on the head, the valve adjuster screw goes in so
far no threads are visible on the adjuster screw.
Without
pulling the head, I’m guessing the valve bent and stuck in the
valve guide. So stuck that the valve spring is unable to fully expand.
Nothing else
makes sense, unless of course I am missing something with
regard to the valve spring.
I needed to
get the car over the Belgian block curbs lining my driveway
and into it’s resting place in my shed.
I removed the
push-rod on the offending valve and put everything else
back on.
Engine will
run, with some encouragement from the throttle. So I’m also
guessing the remaining three cylinders are fine.
Thoughts on
diagnosis so far?
Is it
possible to remove the head without pulling the engine?
With the
valve covers on, I have about an inch clearance to the rear
sub-frame that holds the rear body pieces on the Duchess. That means
about 3 to 3.6 inches with the valve covers off.It’s frustrating. The Duchess has never let me down (ten years with a
stock 1600, 17 years with the 1641).Any thoughts from the VW crowd?
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
Paul sorry to here the bad news.
I don’t think there will be enough clearance to get the head past the studs.Then theres the issue of trying to hold the pushrod tubes and cylinders in place while putting the head back on.All while lying on your back.Best off to just remove the engine put it on a stand.
I think that is number 3 cylinder,some of my research shows #3 exhaust to be a cooling related problem
Thanks oldbuzz. Yeah, I’m figuring I’m gonna end up dropping the engine out. Dang!
But VW Type 1 engine cylinders are numbered like this:
Front of car
3 1
4 2
Rear of Car
Firing order is 1432.
My valve problem is with cylinder #4.
http://z.about.com/w/experts/Volkswagen-801/2009/01/VW-Firin g-Order.png
PMOSSBERG40322.4430324074
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
Will,
I enjoy the pictures. But I’m looking for some input on my engine problems and your pictures have nothing to do with this.
I moved your posts to a new one in General Discussions called Washington Will’s Engine Photos. If you have any more (and they are great!) please post them there.
Thanks man. I appreciate it.
PMOSSBERG40322.4758912037
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
Didn’t think you were making light. It’s just always a good idea to keep a thread “on topic” and not stray away into something else.
Thanks.
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
Ironic,, I just had the same problem. The engine was running fine until I shut it off. When I restarted it it would pop. I also found the pushrod off the # 3 cylinder. I reset the valve clearance and It ran beautiful until I shut it off. Same problem although now I can’t een get it out of the driveway. Getting ready to pull the beast!
I’ll keep updating this thread as the diagnosis continues. But that won’t be for at least a couple weekends.
And anyone with any ideas, feel free to share them.
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
Wow Paul…first class bummer
. At least the engine is easier to remove from a TD replica than a real Beetle. I don’t think you can pull the head far enough off the studs with only 3″ – 4″ of clearance.That’s a good thought about a bent valve, but what made it get that way? Did the seat come loose and hang it open for the piston to smack? Did a retainer (keeper) let loose due to failed valve spring?
I suspect with the head off, you may find piston or cylinder damage too. Have you been on the SAMBA asking questions?
I’ve got my ’69 Beetle’s MOFOCO 1776 “Streetwise” long block about ready to reassemble after a rocker arm “hair clip” went south. Luckily a new valve, retainer, keeper and adjuster screw fixed the head. I also installed SCAT soild rocker shafts…no more “hair clip” or wavy washer problems.
That, indeed, is a mystery.
The valve is solidly retained by the clip. Rocker arms and shaft are fine.
The spring “looks” ok. But like I wrote, it is slightly compressed (about a quarter inch or so).
It’s possible a really loose rocker arm/valve combo could let the push-rod slip out of it’s cup. But even if that happened, it does not help explain the valve stuck slightly open.
Wanna sell your 1776?
PMOSSBERG40323.5426967593
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
Good idea Mark. I posted my story on thesamba.com
The first responder agrees it sounds like a bent valve.
PMOSSBERG40323.6362384259
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
Hi Paul,
Probably an obvious one, but have you pulled the plugs? My experience with VWs is dated but extensive. The most common engine failure I encountered was “swallowing a Valve head” This is clearly a worst case scenario in which the top of the valve breaks off destroying the spark plug and compression chamber and eventually driving a hole through the top of the piston. Let’s hope that’s not it, but simply removing and examing the plugs is proof positive.
Good Luck!!
Rich
Duh. Um, no. I didn’t think to do that! But I will.
It’s likely not the issue. If the valve had broken off, I don’t think the valve spring would be compressed the way it is.
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
If the valve stem bent and wedged itself in the valve guide it would hang the valve open with the head of the valve missing.
The most common failure with valves aren’t the valves, but the seats coming out.
A loose rocker causing the pushrod to come out of it’s cup would not bend a valve…it would just stay shut and make a racket with pushrod getting slammed into the valve cover occaisionally.
However, the valve seat coming unseated, the valve head breaking off would all cause problems in the cylinder that would bend a valve stem hangin it open, then the rocker would come “loose” when the lifter/pushrod were on the “flat” side of the cam, displacing the pushrod from the cup on the rocker.
Weren’t there any VW vendors at Carlisle? The one from western PA always brought a bunch of longblocks.
If you do buy a new longblock, the MOFOCO 1776 “Streetwise” has hydraulic lifters and they never need adjusting. I have a set of Dual Kadrons you could put on it and have an 80 hp, reliable motor. I used this exact set-up in the Pink MG I sold to Bill Collins.
Possibly great news for you! I was talking to my VW guru (Happys VW in New Albany Indiana). He told me that there are washers on either side of the rocker arm. One is wavy and one is solid. If the wavy washer wears out, it allows transverse travel of the rocker arm and it will let the rocker arm move enough to let the pushrod fall out. The washers aren’t available as new parts, but if you can find a junk head you can steal one and be back in business. I did a compression test and found all cylinders between 110-120, so I knew the valve couldn’t be bent. Hope this also fits your problem. Maybe you won’t have to pull the beast after all.
The “wavy” washer failure is what causes the “hairpin” rocker retainer to snap. That’s the problem I encountered with my 1776 MOFOCO motor.
The wavy washers fail because they are old and can’t take the stress of stiffer valve springs or higher lift cams. The “high” spots on the washer wear, the washer comes apart and the rocker arm play slams the rocker into the hairpin clip and snaps it. Then the rocker “walks” down the shaft and off the valve stem and all hell breaks loose!
Paul’s problem is definitely not the same. He’s dropped a valve due to a problem on the combustion chamber/piston side of the head.
Pink MG40325.658275463
Could be, but my symptoms were exactly his. A simple compression test will tell him whether or not he needs to pull the engine.
Thanks dbrock.
Like I wrote in an earlier post, cylinder #4’s exhaust valve spring is partially compressed; about a quarter inch or so.
That means there is about a 99.9% chance that valve is partially open, either because a valve guide or valve seat is messed up or the valve stem is bent.
With the valve open…no compression test!
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
Paul,
Actually, you can do a compression test on #4, but the result will be ZERO lbs.
. Sorry, couldn’t resist.
Rich
Touche!
Thanks for making me smile about this Rich!
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
I just finished replacing the rocker arm assembly on my car. It did solve my problem. After rereading your posts I realize that the valve spring being compressed was a symptom that mine didn’t have. The good news for some, although apparently unfortunately not you, is that the solution that I was given will work. My car runs fine now. I’m also adding a degree wheel to my otherwise stock 1600 dual port.
Always good to hear a happy ending! Now go do some happy motoring this weekend!
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
Hi Paul,
Sorry to hear about your problem.
I blew a fan belt in Tulsa Oklahoma a few years back and noticed the alternator not charging right away and incorrectly assumed it was a bad alt.and kept on going. When I noticed the cyl head temp going towards 600 degrees f i stopped the car but let the engine idle. As soon as I saw the broken belt I turned off the engine and replaced the belt. When I restarted the engine there was a lot of lifter noise on 1 cylinder. THE VALVE SEAT HAD FALLEN OUT! I limped into town and found a Corvair guy who new a good head man. When we pulled the head and checked the cyl with the problem we saw that the valve had pounded the seat back into the head, but a little crooked. The head guy was able to heat up the head to 500 deg f at which point the seat fell out. Keeping the head hot he welded the seat hole up to make it smaller, then cooled it ,machined it for a tight fit and pressed the original seat back in. It has never given me a bit of trouble in 30,00 miles. I was lucky to find this guy!
The biggest mistake I made was turning the engine off HOT. If this ever happens again I will flood the engine buy putting my hand over the carbs first on one bank then on the other, then back and forth 5 or 6 times. all this gas vapoizing in the cyl head causes a lot of cooling right where you need it.
Putting on a good cyl head temp gauge is also a good idea on any air cooled engine. I probably would still be sitting in Tulsa, in a puddle of aluminum, if I hadn’t had the gauge. anyone know where to buy a good gauge? I bought a general purpose one at the auto supply and the nylon insulator melted in a few days. Corvairs use one that has a sending unit that looks like a little spak plug and it works great!
Chuck
Hi Paul
There is one thing you can try before digging into the engine. The valve could be stuckdue to a build–up of carbon or some other stuff (like aluminum-which you would see on the spark plug also,which would mean the piston has gone). If the plug looks ok try this:
1) put the #4 piston in the down position
2) remove the rockers and valve spring from the stuck valve
3)hit the valve down about 1/2 inch into the combustion chamber with a big hammer. Leave some valve stem sticking out of the guide
4) grab the valve stem with a vice grip and rotate it and push it in and out if you can. With a little wd-40 and a little luck you can free the stuck valve. I have actually been able to put valve grinding compound onto the inside area of the stem where the carbon builds up by going in thru the exhaust port on Chevy engines. If you can free up the valve and get it to seat properly you can start it up and check the compression and go from there.
I know this sounds a little scary but what have you got to loose. I did this on my MGA with the chevy 283 engine and drove it for years with no further trouble. On my jaguar I had to tear it down and replace # 4 piston (and the aluminum coated spark plug)
GOOD LUCK and if you need help you can call me at 831 566 6147 today!
chuck
So I’m sure you’ve all been on the edge of your seats wondering what’s up.
Well, life has gotten in the way and I still have not pulled the engine.
Meanwhile, I’ve decided it’s time to dump the 1641 and upgrade to a 1776. I got good deal on a long-block which is on it’s way. I will be able to use the top end off my 1641. And I’m buying new cooling tin.
So…I will have a slightly used 1641 dual-port long-block available for the taking if anyone wants it. It might need some head work!
Paul
PMOSSBERG40361.6472453704
Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
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