-------- Original Message --------
Subject: Re: [Fwd: Re: Engine runs but overheats]
Date: Wed, 31 Aug 2005 21:35:42 -0400
From: John Mitchell <jmitch@snet.net>
To: Sally or Dick Taylor <tr6taylor@webtv.net>
CC: 6pack@autox.team.net
References: <512-43154DB2-11915@storefull-3131.bay.webtv.net>
I need to really thank Dick Taylor for suggesting I do a leak down
test before pulling the head off. Because the new engine had gotten
quite hot during the first run and the thermostat had failed to open I
guess I started to worry about a blown head gasket. Then oil droplets
floating in the radiator lead me to do a compression check showing low
compression in #1 cylinder. Dick suggested a leak down test before
going any further. It was very obvious that it was leaking into the
crankcase as you could feel the pressure coming from the breather and
the dipstick tube. At this point, I figured I couldn't do any real
damage running it, so I gave it another 15 minute run at 2000 rpm. The
engine still gets pretty hot, a little over 3 quarter on the temp gauge,
but it ran quite smoothly considering the carbs haven't been balanced or
adjusted yet. I just rechecked the compression and #1 is within 5lbs of
the rest. I assume that ring is just getting itself seated. You've
made me a happy man!!! John Mitchell 76 TR6( just needs the
interior put back in and I'm cruising:)
Sally or Dick Taylor wrote:
>John---If the head gasket is blown, this can usually be seen as air
>bubbles in the coolant at the top of the radiator. (Give the engine time
>to purge air trapped from cavitation) I would look for this before
>taking off the head. Having the engine apart could expose it to any
>number of contaminants you might later see floating in the coolant
>water.
>Give the "low" cylinder the "squirt of oil down the sparkplug hole
>test". While it would not necessarily be good news if the pressure came
>up, at least you would know that the reason might be something other
>than a blown gasket.
>
>The best way to expose this low #1 cyl. pressure would be to perform a
>leakdown test, which can identify the area of pressure loss 95% of the
>time.
>
>Dick
|