Head Gasket Check
07-21-2011, 04:02 PM
#1
Rennlist Member
Thread Starter
Head Gasket Check
Just got motor rebuilt and new exhaust with magniflow muffler. After a couple of sessions I noticed the car got significantly louder, especially at idle. Seems to have plenty of power, so I checked manifold, exhaust, and muffler for leaks and can't pinpoint any. Changed oil and the magnetic drain plug was metal free after 3-4 hours of track time. When I start it, it sounds like a car with a hole in the muffler.
Mentioned this to my engine builder and his biggest concern may be blown head gasket. My question is how to test for a blown gasket? I have no compression test equiptment and my builder is out of pocket at this time.
Any thoughts? I was going to pull the plugs this weekend to see what that may show me.
Mentioned this to my engine builder and his biggest concern may be blown head gasket. My question is how to test for a blown gasket? I have no compression test equiptment and my builder is out of pocket at this time.
Any thoughts? I was going to pull the plugs this weekend to see what that may show me.
07-21-2011, 04:32 PM
#2
Rennlist Member
Check the O2 sensor....mine had rattled loose and unscrewed itself from the Cat.
Hope it's nothing major?!
Hope it's nothing major?!
07-23-2011, 02:48 AM
#3
Super Duper Moderator
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Could it just be louder due to the new muffler you are not used to? Can you swap back on the exhaust you had before and see if it still sounds odd.
Marc
Marc
07-23-2011, 02:37 PM
#4
Instructor
Join Date: Nov 2007
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
As you describe the sound, I would like for misfits in the exhaust system. Maybe something virbated loose their (or indeed O2 sensor vibrated loose due to corrosion or something). Otherwise headgasket or something, but thats rather odd since rebuild would imply new gasket.
07-23-2011, 04:22 PM
#5
Nordschleife Master
Join Date: Feb 2011
Location: Deep Downtown Carrier, OK
Posts: 5,297
Likes: 0
Received 6 Likes
on
6 Posts
One symptom of a blown head gasket would be the presence of coolant in the oil. Look at yer oil filler cap for a greyish slime....
just had to, it's hot outside...
just had to, it's hot outside...
07-23-2011, 04:54 PM
#6
if its a 964 then there is no coolent in the car its air cooled. if it is not louder when you start it then i would say its not a head gasket as the head would expand as it got hotter make a even titer seal and less noise. if it makes it when it is warm then i would look at the expanding bits.... exhaust gaskets....
Trending Topics
07-23-2011, 06:20 PM
#8
Rennlist Member
Nothwithstanding the humor above re: coolant, the "head" (actually a CE) gasket would be a near impossibility here. Can it get screwed up during assembly? Sure. But you'd know the first time the engine fired.
Now, onto diagnosis. Is the sound in time with all six exhaust pulses, or very rhythmic and noisy on only every sixth pulse? If it's the former, the only place it could be is the muffler. If the latter, everything from the exhaust port on downstream to the muffler.
Now, onto diagnosis. Is the sound in time with all six exhaust pulses, or very rhythmic and noisy on only every sixth pulse? If it's the former, the only place it could be is the muffler. If the latter, everything from the exhaust port on downstream to the muffler.