While I'm down there, should I be inspecting anything else? Seems the popping and decel was worse and worse and worse. I finally jacked the car up and had a buddy turn it on, and I could feel leaks throughout the head areas. Heat exchangers themselves were fine, but several of the rings had failed and were bowed.

I'm guessing this is why I'm hearing so much valve noise since I know that stuff is amplified with any potential exhaust leaks.

I'm not quite sure if the buildup is normal and if I should be concerned or if I should be double checking anything. I only had 2 extra rings (that I could find anyway) and have rags in the holes to keep any crap out until the new rings get here.

Tips? Suggestions? Here is some pictures - wanting to bounce this off to see if this looks normal or not? I'm new to these air cooled engines.

I'm assuming the white is mostly just exhaust crap that has built up over the years? Am I correct? Seems to stop off where the valve obviously goes back in or retracts since you can see head hole #1 is sort of cut off in that spot, the other valve is partially open and you can see it. I believe this means it is holding compression and therefore operating as intended, yes?

Aside from that I replaced some vacuum hoses and the rubber elbow that had cracked where the intake attaches to the vacuum hose back to where the oil gets put in so that's good now

The white is from the additives that are in the gasoline. It appears you are running Smell (Shell) gasoline (ok, so I have something against their additives).

I can't tell if your exhaust stud nuts were loose or if the tops of your down pipes are uneven and they didn't seal. I saw black exhaust deposits in one of the images to indicate a leak.

It would be nice if you could take the HEs to a machine shop and make sure that the down pipes had parallel surfaces. One way is to lay a flat edge across the pair and look for light underneath it, then use a flat file to dress the tops so they are even.

Heat your new gaskets with a MAPP torch till they glow and then let them cool. This softens the copper and allows them to crush better. Small dabs of grease will hold them in place until you put the HEs on the studs.

Get the copper plated "crushed" nuts as they are self locking on installation.

Button it back up.

There is, in your 4th picture, some oil showing on the short block but I can't tell if it is coming from the oil screen, drain plug, or the pushrod tube. Pretty much happens at some point from one or more of those sources, but you can't do much about it without some work if it is the pushrod tube.

If it is the drain plug or the screen gasket, you can fix that and change the oil all at once. AA and Pelican both sell plugs and screens/gaskets. Change the screen if you are the new owner, and look at the old one carefully for anything suspicious.

Hope it is the gasket for your sake. Check the oil level frequently if you can't tell. I had one 914 with chronic leak syndrome. EVERYTHING leaked on that one, but the next owner put it into a pole way back in 78 and walked away. Who knows where the parts ended up? Hopefully not in your car!

Good luck!

John
avidfanjpl

Wow, how did you know? That's impressive!



This is a good point, i used a sanding block with some very fine grit sandpaper to see, they seemed to appear to be flat all around from what I could tell. The rings themselves were bowed (the copper rings) just slightly. I put them side by side to new ones, they appeared to be warped to a very very very small amount. Then again a leak is a leak.



Sounds like a good plan. I can do that.


I got them with a heat gun till they started heating up and let them cool. Torch is better? My neighbor has one I'm sure he'd let me borrow for a few seconds.



Sounds good! So no concern for damage, deposits are normal, flatten HEs to ensure good surface area, button back up, go drive.

Very useful post, thank you very kindly for your time!

The oil on the part you are describing appears to be coming very very very faintly from a pushrod seal. The other amount is the gasket for that top cover that latches on. I will check both next oil change. It's a very tiny leak. I think Jim said he replaced the pushrod seals on one side, I'm not sure if he said he got the other side to be exact. I have extra pushrod seals he gave me, so I suppose next Oil change I can replace them.

Thank you everyone for your time, I wish all communities were this helpful Loving this car! And loving learning it.

Alright... got one heat exchanger back on, got one part of it to seal, the other is being a total pain in the rear. Tried removing and putting it back on. It's COLD air which i thought was.... weird... unless it's coming from that blower motor from under the car but it definitely feels like cold air.

The other heat exchanger on the other side is no doubt leaky on the seal as I can put my hand there and feel the heat hitting my hand like warm wind.

This side is mostly sealed up. One is totally sealed, can't get the other. Going to try resealing again and torquing down a bit more and see if I can't get it to stick.

Will report back. Probably not gonna get it done in time to drive it around tonight - gotta go to work in about an hour and a half. :-/

You can attempt doubling the gaskets to get a seal, but planing of the downpipes would be much preferable.

Ok went back outside and i'm sort of baffled. If I get my hand VERY close into the header I only feel the cold air on the BACK side of my hand.... move it a bit more, can feel it on the front of my hand.

I would assume any air from the car would be HOT air coming from the header, especially that close to the header, am I correct?

Can feel NO air on the other portion of the header, pipe #2. Am I feeling air coming from elsewhere? It feels just as cold as the air coming out of the fan motor air. I truthfully cannot tell where this cold air is coming from if it's an exhaust leak or coming from up above me.



I went after the tips with a sanding block and started with 180 and went down to 300+ grit to get a nice seal. There was pitting and some small low spots in it, it seems to be flat now.

Retracting my previous statement and claiming brainfart - the air on back of the hand is coming from ABOVE the engine - the fan... there is NO HOT AIR coming from the header anymore at this time. This side is sealllllllled! Time to tackle side # 2 and sand that down as well.

The car is already starting up a lot easier.

I would have told you that cold air was coming from somewhere else. Exhaust temp, at the port, is somewhere between 1200 - 1600 degrees F.

Yes, the fan sucks in cold air and blows it over the cylinders and then the air exists out the bottom.

Andy

Alright then, so in that case we definitely have it sealed up on one side. I'll do the other side later tonight. I gotta head back to work for some massive overtime. I'll let you all know how it goes later.

But just a quick summary - upon sanding down the tips of the exchangers there was a lot of pitting in them. I've sanded it down to fresh metal. But there's definitely exhaust leaks one the other side as you can head the audible clack clack clack of an exhaust leak. The only heat coming anywhere on the driver side exchanger is just the off heat from the exchangers themselves being hot.

But i'll take some pictures of the exchanger rings later, there was quite a good amount of leaking past them. Oddly enough - you could see black rings embedded in the tips of the exchangers. Not big ones, but I could feel them with my fingernails.

If this time around doesn't fix it I'm bringing them in to get milled but it looks like I've got it.

I appreciate the help everyone.

Pics of the old seals

Took lots of pics and will post results - exchanger #2 had a lowspot on the end on both ends of it - required a LOT more sanding than the 1st exchanger. Waiting for the copper seals to cool down and taking a quick break before i head back out to finish the rest.

Ok all the heat exchangers are back in and installed. I can't hear anymore clicking - can't feel anymore heat and everything seems fine. Won't know till i actually go drive it how it's feeling or not. But everything seems in order.

I crawled under the car while it was up on stands and on and cannot hear anymore clak clak clak. It's MUCH quieter now.

I also replaced the fuel line from the tank line to the fuel filter (the weird funky old braided one) as it was damp to the touch and pretty much ready to fail. Jim provided me with a new one and advised me to change it, so i did that as well while I was under there. Peace of mind. Granted I got a chemical burn from laying in gasoline for a while while I replaced it, we're good to go now XD

Thanks for the assistance and advice everyone!

Ok now i'm not sure what to think.

I went for a drive to test it out tonight. I heard ONE POP. I thought "SWEET! this thing is fixed for sure."

About 1 minute back from my way home, decel... POPOPOPOPPOP.... i thought "Greaaaaaaat" I get out, put the car in neutral, e-brake on so it stays still, go climb up near under the car and sure as hell I can hear the unmistakable sound of exhaust leaks.

What am I missing here? It was great every single time I started it last night, revved up and down, no issues, sounded awesome.

Went for a drive.... now it's back. Too frustrated right now to get it back up on stands and look at it.

Found the culprit - I seem to have a small leak up near the muffler itself. I'm getting water from the tailpipe (as I should). I go up near the exchangers... no noise... feel with hands.... no noise....

Get my head up near the END of the exhaust and I can hear it.

Does not appear to be the end gaskets on the exchangers. My ears like that.

Get up with a tube to listen and I can hear up towards the muffler.

What i do know is that SOME people put holes in the muffler to keep water out of it. I cannot see well enough up in there to tell if indeed that's what it is. BUT water comes out the end of the muffler, and trails back from some point on this muffler, so there is a hole up in there somewhere which is the final clicking.

I think i was just freaking out because the way it reverbs off the concrete sounded worse than what it was when it's back up on stands.

SO - since i'm still getting popping - it's either because of this leak - or my timing is off - or my mixture is too lean.

Either way - my heat exchangers are happily sealed - so at least I have the satisfaction of knowing that's fine. The leak is elsewhere.

Going to leave it up on stands till I can pull it apart and visually inspect it. Also going to check the timing. Then going to check the lean mixture. After that, I'll go drive it.

Until then - looks like I'm driving the 944 back and forth.

This is turning into a dear diary column for me.

Time to go have a drink.

Dear diary - today i got pissed off at exhaust leaks - i fixed them, found another - so i called my car funny names and had a mixed drink and waited for the 914 members to laugh at my silly assumptions of thinking i had more leaks.

On the happy side - my fuel lines are happy.

Here's pics


















Finished


And given the last touch with 300+ grit

Two things ...

It could be a crack in the muff that doesn't show until it's heated up (serious statement)

And, rather than lean or rich, do you have the deaccel valve hooked up?

Could be - the way it's coming up sort of looks like it may be coming from up near a weld. I'll only be able to tell by pulling it apart and finding out I suppose. Shouldn't be hard to find out. I'll look into it.

As to decel valve - i'll find out - thanks for the tips

seeing as you've had the hes on and off, have you replaced the he to muffler gaskets? they have a slight ridge in the middle that seals the individual pipes and the ridge compresses over repeated removal.

i haven't replaced them but double checked them for leaks - i can't feel any direct leaks or hear any leaks coming from them. it's definitely upwards towards the muffler in the center up above the gaskets you're talking about. Not a bad suggestion though.

http://members.rennlist.com/pbanders/DJetParts.htm

Tells me that my year of 914 does not have a decel valve (1970). Drove it to work today and it sounds better. Weird - didn't hear much today.

Corrected some of the vacuum lines on the intake and the aux air valve - seemed to help a little. There is one more on the aux air that needs replaced. It's a tiny 1 inch piece of hose but it looks like the edges are cracked.