Massive Coronary only Minutes from the Marina
- Thread starter RobertLangdirect
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And he told you that you probably have the beginings of a blown head gasket .... and the location of the blown gasket is probably between two cylinders - usually between #3 & #4. ..... and you havent re-torqued the head in quite a long time ..... !!!!!!
If it were one of the notorious stuck A4 exhaust valves you wouldnt have a complete shutdown as an A4 is quite happy to lug along on only 3 cylinders.
Dont forget that the A4 is a *studded* engine to hold the head down ....; and, Stud-pullers are cheapest from Snap-on Tools !!!!! Dont forget to reseal the studs into the block when reassembling.
;-)
It obvious
That some of us are more gearhead than others. No suction means no compression. No compression means no run. Has nothing to do with spark.
That some of us are more gearhead than others. No suction means no compression. No compression means no run. Has nothing to do with spark.
if memory serves me well the A4 is a L head engine(meaning flathead and the valves will be beside the pistons and not above them)...the only way a valve could hit the top of a piston is to have broken off at the stem where it comes out of the seat and maybe wandered over on a pistion...but most likely not...just a though here........
regards
woody
From the moment I read the post my thought was timing chain or gear and now that I read about the head might be the problem it could be either one cause Robert said the engine was being stubborn earlier.....checking the timing is real simple to eliminate that part of the equation
Ok, my thought is a break or void in the intake manifold prior to the carburetor. Is there a vacuum hose, plug or cap that has failed?
Mine did have and exaust valve fail on teardown SO i put in 4 new ones
There are NO easy to reach timimg gears on the A4 as they are all in the back of the motor driving the cam/oil pump/ other stuff
Start with a compression test and work from facts not a WAG guess
There are NO easy to reach timimg gears on the A4 as they are all in the back of the motor driving the cam/oil pump/ other stuff
Start with a compression test and work from facts not a WAG guess
Guys! I posted, in a different font, more information about the motor and how it has gotten progressively worse. I DEFINITELY amd goint to either a friend who has, or Harbor Freight to buy, a compression tester. I think we will find, NO COMPRESSION, but YES YES YES, lets do some factual study and find out.
One more fact, OIL pressure was always "GOOD." I do not remember the number in the middle of the guage but it was and still is centered.
OH, one more nice to know. This boat was hit by a hurricane, had a large hole in it, and then sat on the hard, filling with water, over five years. The oil was NOT contaminated (not brown or chocolate like, or with beads of water), and I changed the oil, more than a few times over the process getting the motor UNSEIZED.
SEIZED? Well yes, and it took many hours of break free, foamy penetrating oil, kerosene, WD-40 (kerosene with a dollop of lard), and back and forth with a wrench to get her turned over.
Looking to do all thing in due time, having an old crappy motor running was important. I did not have the where-with-all then to pop her out and rebuild, or even pop her out and take it someplace.
SO: PLEASE, who sells rebuilt A4s? Who rebuilds A4? Names and City, URL, or tel no, please. And thanks again to everyone for weighing in on the post.
One more fact, OIL pressure was always "GOOD." I do not remember the number in the middle of the guage but it was and still is centered.
OH, one more nice to know. This boat was hit by a hurricane, had a large hole in it, and then sat on the hard, filling with water, over five years. The oil was NOT contaminated (not brown or chocolate like, or with beads of water), and I changed the oil, more than a few times over the process getting the motor UNSEIZED.
SEIZED? Well yes, and it took many hours of break free, foamy penetrating oil, kerosene, WD-40 (kerosene with a dollop of lard), and back and forth with a wrench to get her turned over.
Looking to do all thing in due time, having an old crappy motor running was important. I did not have the where-with-all then to pop her out and rebuild, or even pop her out and take it someplace.
SO: PLEASE, who sells rebuilt A4s? Who rebuilds A4? Names and City, URL, or tel no, please. And thanks again to everyone for weighing in on the post.
- Dec 30, 2009
- 680
It could be something as simople as a spun dist rotor...To rule out fuel spray a little starting ether in the carb hold the choke open if it closed when you spray. Be careful when u crank get your body out of the way stuff is flameable, if it does not turn over its probably not fuel problem. I would then check for spark. good luck...Red
Quite a mystery, Robert.. Just have to ask.. did ya open the tappet gallery cover and clear that out ?? Would require removing carb and possibly intake manifold.. I had a problem many years ago where an old, formally seized (hurricane driven salt water) flathead 4 cyl Jeep engine stuck all of its exhaust valves open after a short run .. The corrosion goo had fouled the tappets and valve stems and the heat of running (without having cleaned that up) kinda set the goo so it stuck the valves. That is a fairly low flow area and might not get clean from flushing alone. The "Stump The Chump" show MUST have pictures as you solve the puzzle !
A blown or even weeping head gasket between two cylinders can cause water leakage in a cylinder. The most common place for an A4 to blow a head gasket is between #3 & 4 cylinders.
Suggest that if you find compression anomalies you remove the head, while still in the boat, and inspect the head gasket. Pulling the head on a studded engine is not 'easy' and can risk breaking off studs or pulling them out from the thinned block .... get a stud puller to remove the studs. If you break studs you can replace them by cutting common shoulder bolts, just be sure to seal the threads that fit into the block with sealant ... Permatex.
However, the MOST IMPORTANT consideration when thinking about rebuildiing an A4 is the 'amount of metal still remaining in the block'. A4s are rebuildable if the engine hasnt corroded away internally. The "TEST": remove the exhaust manifold; then, go into the bore holes of the manifold attachment bolts with a pick or dental probe and COUNT how many threads are remaining. If you have FOUR or more threads = rebuildable; If less than FOUR threads, then dont bother as the metal thickness is no longer sufficient for a rebuild.
A4s, if not rotted away internally, are easily rebuildable. www.moyermarine.com sells rebuilt 'short blocks'. They also are beginning to build completely NEW A4s, as they are able to have the components cast and new crankshafts, etc. Even a brand NEW A4 will be probably less than HALF of what a diesel replacement will cost AND a replacement diesel will be almost TWICE the weight of an A4. A diesel replacement will require a complete replacement of the fuel tank etc., propshaft/prop, engine beds, etc. etc. etc. ... so figure those cost estimates in the price of a diesel swap-out.
Check out that compression, check the metal thickness at the exhaust manifold bolt holes, pull the head to inspect/replace the head gasket, etc. ..... BEFORE you jump-the-$$$$gun and 'repower'. If you need to repower, talk to Don Moyer, FIRST.
hope this helps.
DO NOT TOUCH THE STUDS AS THE HEAD HOLES HAVE PLENTY OF CLEARANCE
Remove the nuts and spray as i have had no issues removing BOTH of my A4 heads
Remove the nuts and spray as i have had no issues removing BOTH of my A4 heads
Disagree with that. What you dont want to do is complete a head gasket job, and then find out when done that when retorquing that you break off a stud ... and have to do the job all over again. Restudding is fast easy if you have the RIGHT tools.
Red,
It is no longer sucking air through the carb. Ether does not start the motor. However, I will pop out a plug and sent a small shot into the cylinder. I am confident that will "pop" on the first cycle.
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