505 engine into 504 FOLLOWUP

[82' 505 and Crusin']

well i have done this swap and started it up today.

It started first go but it was blowing a little smoke. I had it running for about 5 min. I then checked the water and to my dissapointment, the water was foamy (head gasket?)

The engine was good and had been tuned before it was removed from the 505!.

What does this mean?
How can this happen?

 

[Gus]

Hey Joe,

Here's what comes to mind:

- Coolant goes off after about a year or two, at which point it can do all kinds of strange stuff. Also, are you sure the coolant you put in was clean?

- You also have no guarantee of what was in the 504 radiator, unless you flushed it. The watery stuff in the 504's old engine would imply that _it's_ head gasket was blown, which would mean an oily radiator. (it's the oil that makes the coolant froth, or so is my understanding.)

- My 505 will froth its coolant if you rev the engine hard in neutral while warm. I had it tested with a TK Sensor (at a garage) and there was no exhaust gas coming from the radiator.

- If your head gasket is blown you should (probably) see one of (a) frothy "chocolate milkshake" oil due to coolant in it or (b) white, sweet smelling, smoke which "hangs in the air" coming from exhaust - not just the condensation steam you see when warming up at this time of year.

- Is ur water pump hooked up? (This one got me initially when I converted to electric fan )

- That 504 wouldn't have been run in a while, and it's still got the 504 exhaust. I once got a Nissan straight six started that had been sitting for nine months, it blew thickish black smoke for the first few minutes and I reckon that was nothing more than accumulated crud from the exhaust. (It's possible it was a blocked air filter, though.)

Apart from a TK Tester, you can check for a head gasket leak by:

- Revving engine and checking for a "steady stream of bubbles" in the radiator.

- Starting engine cold, removing radiator cap, revving engine hard (wait a few secs for the oil to get around inside first). If the gasket is properly blown, the extra compression pressure in the radiator will cause the coolant to gush out the radiator cap (while warm, the coolant is apt to boil and do this anyhow! ) You may have to wait for the thermostat to open first, though (not sure.)

One last idea:

- If you don't bleed the system when you're filling it with coolant, you'll have air bubbles... Maybe that's enough to bubble/froth the coolant some ...

 

[fiveohs]

Jofus

Don't jump to conclusions yet. Yes a partially blown head gasket or liner seals could cause this, but so could a leaky water pump, or leaky hose, or bubbles trapped in the engine when you filled the cooling system.

Drive it around a little bit (but not too far from home). Flush the cooling system out a few times, and drive it around some more. See if the foaming persists.

If you have milky oil as well as foamy water, then you probably have gasket or seal problems. Don't drive engines like that around unless you want to kill your big end bearings and put a conrod through the side of the block (like I once did). Watery oil doesn't give very good oil pressure.

Slightly milky oil, on its own, can mean a blocked crankcase breather, which is easy to clean out.

Dave

<small>[ 22 June 2002, 10:39 PM: Message edited by: fiveohs ]</small>

 

[82' 505 and Crusin']

I havent checked the above ideas yet, but running it today, it stopped blowing tha smoke, i guess that was just burning 6 months of dust.

But the water was still foamy, so I flushed the radiator (cold water). I filled it up with water and I could see oil floating, before i even started it, So as Gus said, it was proberley oil in the radiator, from the previous engine with a blownn head gasket. I have a spare radiator so I will try that.