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Compression seems okay, opinions please...

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I'd like a little more input from y'all regarding my '72tii engine. I posted a note about a possible head gasket failure a couple weeks ago. Here's the link:


Compression numbers from this morning are (psi, engine cold):

1 - 174

2 - 165

3 - 170

4 - 180

Is #2 too low? There's no white milky crap on the oil filler cap or dipstick, oil and coolant look clean. I suppose I should warm the engine up and try again. Is it likely to make much difference?

How does one diagnose a blown brake booster?

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check for any loose head bolts - if any are just spinning

loose - you have a broken head bolt

Just put a socket to each head bolt and

check each for tightness

adjust the valves COLD to 0.006"

before replacing the cam cover - check the center

banjo bolt for the oil spray tube for tightness

DO NOT OVER TIGHTEN!!! you'll snap it off!

change the oil and filter (15w/50 or 20w/50 only)

drive 250 miles and report back

p.s. your compression reading are spot on

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Your numbers look pretty good, but after doing mine cold this morning, I did the compression check again after doing a search, finding that everyone was saying to do it with the engine hot.


1 120

2 100

3 134

4 134


1 195

2 180

3 160

4 160

I was surpised at the difference between cold and hot, but I knew my engine was questionable because the valve adjustment excentrics are worn beyond being able to be adjusted anymore on some valves. Also, on hills in 5th gear there has been loss of speed that I didn't remember from other cars I've had.

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How is your brake fluid level? There is the possibility that the master is leaking into the booster and some fluid is getting sucked into the intake. That doesn't explain why your radiator was low but it sure would explain the nasty smoke.

Did this just start suddenly or what? Has any work been done on the engine recently?

A leak down test would be good........


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Head gaskets can fail in any number of ways-

it's pretty common for the cooling jacket to

fail into one or more cylinders. Often, then, you get

very few symptoms except water comsumption, and maybe

some coolant smell at startup.

Sadly, this can also be the symptom of a head with a crack in it.

Milky oil is a failure from coolant to oil return,

and low/no compression in 2 adjacent cylinders

is a cylinder-cylinder failure.

Your compression is fine...

I agree, a leakdown would help. Do the first check stone cold, with the

cap off the radiator, and look/listen really carefully to see if any air's

coming out the radiator. Then do one hot- if you warm the car

with the cap off, you can again check for air out the rad. Much of that, though,

would mean that your radiator should have already exploded...

(ask the man who owns one...)



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