water in oil from exhaust?

[joe_db]

If the block is cracked, you need a new engine and a new exhaust. If the block is not cracked, you need a new exhaust. There is no scenario where you do not need a new exhaust.
A4 exhaust systems are wear items. I have replaced mine probably 5 times at least since we got the boat in 1977. It really is no big deal, you go to the local plumbing store and grab some pieces and have at it.
What you are doing now is like trying to troubleshoot the shock absorbers of a car that only has 3 tires.
EDIT - is this engine FWC? If so, having a cracked block from freezing is very unlikely unless someone literally used fresh water as the coolant. You really need to start with the relatively cheap and easy solution. Exhaust-making is kind of a hobby for A4 owners, give us a few dimensions and we'll have your setup for you

[afsam94]

lower water line

Looking at Whippet's generic exhaust layout above my water line is much lower probably at the level of the lift so the exhaust at the manifold level remains above the water line even heeling

[Ram41662]

Afsam, I understand your frustration, I've experienced some with this silly engine myself.

One thing I discovered was these engines will run deceivingly well on 3 cylinders or with minor leaks in the head gasket. On mine, I experienced two problem. The first was two cylinders had gunk interfering with valve seating. This was easy to ldentify with a compression test. The second problem was leaking from the other two cylinders. That I identified with a bleed down test. The pressure loss could indicate bad rings, worn cylinder, or as in my case, a bad head gasket.

Why I mention this is a bleed down test will show a leak from the cylinders and could give you a clue as to if your head gasket is leaking and allowing water in. It might also allow you to isolate the section of engine where the problem lies.

Another option is you might try a pressure test on your cooling system. A quick 15 psi test showed I had leakage in my engine which turned out to be the head gasket.

FYI, neither of these test will identify if it's a cracked block versus a leaking head gasket, but they will give you path or eliminate some possibilities.

[afsam94]

pressure tested last year twice

I followed the procedure for pressure test on the cooling system from Don above (the one with a reducer bushing and schrader valve) last year (twice) and the pressure held for the required amount of time.

What is a bleed down test please? Is that the same as with the schrader valve?

Another question. How difficult is it to replace just the manifold and the exhaust riser shown in the links shown in my post that starts "You mean" above? I know I have to pull off the heat exchanger that sits on the outside (easy) but then what? My biggest problem is that the straight exhaust is very difficult to get to. No flange on the outside of the manifold. more like it is just screwed to the manifold but rusted and corroded like crazy. One pro said he would try but if he snapped it off he would not buy me a new manifold.

I have got to do actual work on my boat today of another sort so I wont be replying until late. Thanks

[joe_db]

This piece bolts to the manifold and the pipe screws into it:

https://moyermarine.com/product/exhaust-flange-exht_04_127/

[Ram41662]

Afsam, a bleed down, or "leak off", test is a compression test in reverse. It's best done on a warm engine, but it can be used to find problems on a cold engine as well.

The test involves positioning a piston a top dead center with only that cylinder's spark plug removed. With a bleed down gauge, in the case of a single dial device it look like a compression tester with some additional plumbing to allow you to inject compressed air 8nto the cylinder, you pressurize the cylinder and watch for the rate of pressure loss. No engine will be completely sealed, but a the standard accepted loss is about 20% over 5 minutes, or at least that was how I was taught.

Here's a good link to website with more info: https://mobiloil.com...how-to-do-a-leakdown-test

Rick

[Ram41662]

As for replacing your exhaust at the engine, I'd like to see a few more pictures right at the point of attachment to the exhaust manifold before making any solid suggestions.

If it is like you say and it's truly threaded straight into the manifold, I'd been tempted to saw it off very close to the manifold the chisel out the remaining pipe. Next, if there are no threaded holes for a manifold flange to be bolted to, I'd drii and tap a set in so I could use standard equipment from then on.

Again, that is an opinion base on a lot of assumptions drawn from the limited info so far, so please don't consider it a "cast in stone" solution.

Rick.

[joe_db]

What the back end of the manifold looks like. If someone actually tried to thread the manifold itself instead of buying a flange, they likely broke into the water jacket

[afsam94]

When you're right you're right.

When you're right you're right.

I did crazy things when I was young and stupid 10-15 years ago (I'm 68 now) when I removed the asbestos from the the entire exhaust:

• I did add a flange from a plumbing supply place
• So the exhaust pipe IS screwed into the flange not the manifold
• I did gunk it up with high temp gasket sealer
  
• I put a hose clamp on to hold the gasket sealer stuff in place until it dried
• I never took the hose clamp off. (so no that clamp was not intended to have any structural value

See picture

[Ram41662]

Okay, you win the "Bodgered Repair of the Day" award for that one. 🤓

[joe_db]

Step 1 - buy the flange designed to fit that and pressure test the manifold.

[Whippet]

but...

Looking at Whippet's generic exhaust layout above my water line is much lower probably at the level of the lift so the exhaust at the manifold level remains above the water line even heeling

even if the whole thing is far above water line - from your photo, looks like the exhaust hot water entry from engine is at same level as manifold. what is to keep water from flowing right into engine?

As said, most of the parts we are discussing come from any plumbing store (use black pipe, not galvanized), and hose from marine store. Moyer sells convenient part for exhaust water entry.

[afsam94]

The exhaust exit at the stern turns out to be elevated about 8 inches above the level where the exhaust exits the manifold and the manifold exhaust is close to the water line.

I've decided to move immediately to replace the straight pipe with an appropriate riser configuration. What measurements or pictures do I need to order the correct parts please? OK I just see now that you suggest I CAN get appropriate materials from plumbing suppliers

(A real bodger might sadly have chosen wood glue but I accept the compliment.)

Sorry I posted this before reading the two additional reply posts. So you suggest adding the Moyer flange and pressure test? The engine is running fine currently. Shouldn't I try to get the current flange off first? Is the current flange hopeless if I am fortunate enough to pipe wrench that straight piece off? I will call Ken in the morning to get his feed back and suggestions as well.

I can't thank everyone enough. You have dragged me kicking and screaming into the twenty first century exhaust world.

Note bodger link corrected

[roadnsky]

So you suggest adding the Moyer flange and pressure test? The engine is running fine currently. Shouldn't I try to get the current flange off first? Is the current flange hopeless if I am fortunate enough to pipe wrench that straight piece off?

YES. Yes, get the proper flange on there.
Here are some pics of a proper "rise" system...

[Peter]

It has already been mentioned that you should get black pipe as opposed to galvanized.

Why you may wish to know?

Galvanized will give off toxic fumes when it it heated.

I had to go to a plumbing supply store as opposed to my usual hardware store to get the black plumbing.

Stay safe,

Peter