Hi there,

as I got so many useful tips I thought that I write up something that seems to be a typical story for my fate as an amateur mechanic, and a question at the end.

My 37 Roadmaster had some overheating problems. This started after I renewed the exhaust system (Waldrons), had the carb overhauled, inserted a new thermostat (from Bobs) where there was none before and had the ignition timed.
Well - after playing with ignition timing and some consulting through this panel I decided to flush the whole cooling system with an acid that I got from a local radiator rebuilder to dissolve any lime and muck. I also removed the thermostat again. I chose this one because it did not require a lot to dismount.
So far so good, after extensive flushing, I filled in distilled water, took the car for a spin and happily noticed that the overheating problem was a lot less severe - or gone.
One week later you can imagine my face dropping when I discovered a big rusty puddle under the engine and 5 pints of coolant missing. The oil was still clear.
When I start the engine, it coughs up a bit of black water through the exhaust - just for a few seconds, but enough to notice. There is no pressure in the radiator and no oil either.
I found out that the coolant seems to be leaking between the rear end of the engine and the fire wall - the best place to not get to or see anything. So the acid tratment may have eaten up the cylinder head gasket - if not worse.

I have to make a decision now:
Just exchange the head gasket - or spend an extensive engine overhaul? I am dreading what I discover when I remove the head. But I am dreading the bill for a complete engine overhaul as well.

1. Any comments or recommendations?
2. In order to remove the radiator, do I have to remove the nose? I know how to unsrew the grille, but am not so sure about the whole front part.

Thanks as always for advice,

Christian

There's not tons of bracketry to remove like on a modern V8 that you'd take off to remove both cylinder heads...its a lot simpler. Pull that head and have a look. I'd guess you cooked your gasket. These heads and blocks are REAL thick, especially the big 320 CI engine as in your Roadmaster. I'd be real surprised if acid burned holes in any of the walls. Was this...something like straight hydrochloric acid or diluted like say more on the order of drain cleaner perhaps?

For the radiator removal, just remove the grill and the hood. The hood is held on by two bolts, one up front by the hood ornament, and one up above the radio. Be careful removing the radio, if you drop it on your head, it will do some damage (to you). You will need two people to lift off the hood.

Next, you have to remove the fan and the water pump. Now the radiator can be lifted out. Again, two people are recommended - send me a ticket to Germany, I'll be happy to help.

Jeff

Jeff,
thanks for the advice. If all things fail, I´ll remember to send you a ticket. Maybe there would be some time for a spin through the black forest ;-))

Christian

Try getting a flat small mirror behind the block near the firewall. There may be a core (freeze) plug that is leaking.
Good Luck.
Joe, BCA 33493

I agree with Joe. The freeze plug will be in the engine block and not the head. You have two options to fix it. Remove the engine or make an access hole in the firewall from under the dash. I had this problem with my son's 29 Buick and found a flap that was made by the previous owner or his very clever mechanic.

He drilled 1/4" holes in the firewall from inside the car. By drilling a U shaped pattern, he made a flap directly opposite the freeze plug that allowed him to replace it without removing the engine.

Hi there,
thanks for all the good advice. as there is less than a quarter inch between firewall and engine block, the mirror thing didn´t work and with my fingers I couldn´t feel and freeze plug. Also in the shop manual there is no hint for a freeze plug and I believe that the 37 320 engines didn´t have one.

Another interesting thing was that the leakage stopped again by itself. I had the car out for a spin in wonderful autumn weather, and there was no more leakage. Doesn´t solve the problem though on long term.

Another question: the engine blows out quite a bit of smoke (whiteish, smells like exhaust fume and gazoline)through the crank case ventilation and also through the valve cover ventilation. Is that a sign of piston ring wear?
There is no oil in the coolant and no water traces in the oil, so the head gasket could not be blamed for that. Any hints? Oil pressure ia always excellent.

Christian

Are you kidding? Quite a bit of white smoke? Stop driving it, Christian. You know that's steam, and it's coming from a head gasket leak. You don't need a major overhaul (yet), but it would be wise to pull the engine, put it on a stand, and pull the head to inspect the gasket. While you're at it, remove all the freeze plugs and carefully inspect the water jackets around your cylinders. Use a wire hanger to probe around cylinders. If you find lots of rust, have it flushed, then replace all the freeze plugs with brass. It sounds like you don't need new rings or bearings, but I would pull the oil pan, just to look inside for water or foam (throw the oil away, too). Water makes a horrible lubricant, and promotes rust. Engine heat will evaporate as much water as it can but the oil still gets contaminated and must be discarded.

Pulling the engine isn't as bad as it sounds, and there are not many electrical or mechanical connections. When your engine is out, everything is exposed around the engine bay, as well as the engine. That makes for a good opportunity to paint everything before you assemble.

While on the stand and because the oil pan and head is removed, unbolt #1 piston and pull it out. Carefully remove a top ring and place it back in the cylinder. Using the piston, push it in about 3" (50mm), and measure the end-gap with a feeler gauge. If it shows wear of more than .020", consider buying new rings.