Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 924/944/968 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Aug 2003
Location: Bothell, WA
Posts: 86
Head and Gasket Questions

Well, I got the 83 944 head back from the machine shop and all was well. I thought the valves must be bent, but nope. $65 bucks and looks like new. Thank goodness for a friend in the auto repair business.
BUT, I'm still concerned, because of the way the car ran. The head gasket looked bad but not blown. Frankly, the head didn't look bad when I removed it. There was a noise that sounded like a valve or something wrong on the top end. Also the leakdown test was like 4%, 30%, 34% and 18% front to back. I haven't examined the head gasket closely, but it did look "rusted" in some spots. I've had blown head gaskets before and I don't see anything dramatically wrong with this one.
The lifters and cam all look perfect, as do the cylinders.
Any ideas?
__________________
83 Silver 944/Auto/Cookie Cutters/No side strip moulding/Extra Saratoga top(w/no hardware though)
1980 Yamaha XS1100 Special My other project and daily driver

My kids say my hair matches the color of the car! Who's getting old?
Old 02-13-2004, 11:37 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
tobster1911's Avatar
 
Join Date: Jan 2004
Location: Colorado Springs
Posts: 869
My 2 cents worth.....

Possible causes for low compression include (top down)
1. Bent Valves (very bad)
2. Scored Valve seats
3. Bad head gasket
4. Piston Rings

Did the machine shop actually disasseble the head and check the valves for tolerance?

I just had to go through the head of my '87 944S. Bent all the exaust valves. Damn timing belt.....
__________________
***************************
'97 Saturn SL (tiny 1.9L bubble car)
'98 Grand Prix GTP (4dr family car with a bite FOR SALE)
'87 944S (Sold as a German engineerd money pit)
'78 Chevy 4x4 (What I drive when everything else is broke)
Old 02-13-2004, 01:43 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
Join Date: Aug 2003
Location: Bothell, WA
Posts: 86
Well that's a good question. A friend of mine who has an "auto salon" sent it out to a shop they use. I know they pressure tested it. I hadn't inspected the head gasket all that closely yet. I left it sitting in place until I was ready to clean and prep everything. I'll be home in a couple of hours and will certainly be checking it out.
It's the metallic noise throughout the RPM range that made me think it HAD to be bent valves. Ran real rough at idle, fine above 1000 rpm.
thanks.
__________________
83 Silver 944/Auto/Cookie Cutters/No side strip moulding/Extra Saratoga top(w/no hardware though)
1980 Yamaha XS1100 Special My other project and daily driver

My kids say my hair matches the color of the car! Who's getting old?
Old 02-13-2004, 02:04 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
FLA944's Avatar
 
Join Date: Oct 2002
Location: Palm Bay, Florida
Posts: 317
Send a message via AIM to FLA944 Send a message via Yahoo to FLA944
Please tell me you did not reuse the head gasket.

did the machine shop plane the head?

Did you apply assembly lube to all contact points and fill the lifters with oil?

Did you apply assembly lube to the head bolts and torque in progression per the manual?(for accurate torque)

What is the compression? good compression = rings ok. Leakdown is either valve seats or head gasket.

Oh yeah forgot, low rpm NG above 1000 ok could be the intake gaskets. Use a bernzo-matic torch UNLIT! and wave around the intake mount and afm connections etc. and look for a change in rpms

Rick
__________________
'83 944 "Guards Red"
New Everything (seems like)
16" 968 Wheels
has never left garage (yet)

Last edited by FLA944; 02-13-2004 at 02:50 PM..
Old 02-13-2004, 02:46 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 03:03 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.