Mitsubishi Forums banner
1 - 7 of 7 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Hi All
Just finished a complete rebuild of my 2003 outlander engine) after an overheat. got a recon head ( The one I took off as it was badly overheated so it was scrapped). Bottom end hone, new pistons bearings etc. Everything went smooth measured in spec, used high-quality gasket kit and new head bolts which were torqued according to the manual which matches the instructions received with the bolts, the timing is all spot on, new plugs, water pump, and started up on the first crank. No leaks etc.
It sounded like I had a vacuum leak, so I started trying to find the missing pipes that are normal after a rebuild, found the brake booster, which I promptly attached and the car was still rough.
I was about to get new plug wires but thought I would give it a compression test to rule out anything internal.
It looks like I have a major issue with cylinder 1 which is reading 50psi compared to all the rest at 175psi.
I have checked all rockers the valves all seem to be behaving. Borescope confirms that all the pistons still look new i.e. no valve conneciton.
The head gasket could only go on one way, deck and head were both flattened before the build as well. All cylinder head bolt holes were checked before the head was installed to ensure there was nothing preventing the bolts from easily threading to their max depth.
What am I missing?
 

·
Super Moderator
2004 TL Magna(aka Diamante) AWD, 6g75 engine, F5A51 automatic trans.
Joined
·
163 Posts
I have lost touch over the years with the finer points of compression testing as I have not needed to do it for a long time, but have you done a test after squirting some oil into the cylinder to see if the oil seals the rings?

If not, I will leave it up to you to look into the finer points of exactly how to do it.
 

·
Registered
2001 Eclipse Spyder GT. V-6 [6G72].
Joined
·
45 Posts
"Complete Rebuilt" ? Low compression in one cylinder...What is wrong with THIS picture ???...Sounds like what we call a "Rattle Can Rebuild". Something wrong here. ...J.D.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #4 · (Edited)
@WhiteSpyder, I wish it was a "Rattle Can Rebuild" then It wouldn't have taken so long, had everything replaced, measured engineered. Am a bit invested in geting it working now. On the up side I was told by the engineer that it could be a lifter. Said to compress the valves on the intake and exhaust for a day each. If that doesn't work, replace the little buggers and try again.
Thanks for the input anyway.
 

·
Super Moderator
2004 TL Magna(aka Diamante) AWD, 6g75 engine, F5A51 automatic trans.
Joined
·
163 Posts
Have you tried to carry out a test with a Vacuum Gauge?

How to Use a Vacuum Gauge to Diagnose Engine Problems



VG kits are relatively cheap to buy, and easy to do.
 

·
Registered
2001 Eclipse Spyder GT. V-6 [6G72].
Joined
·
45 Posts
When I was a young guy bumming around the used car lots of Southern California, I would quite often carry a vacuum gauge in my pocket. Sure can tell a whole lot about an engine in a couple of minutes. Kind of hard for a salesman to argue with you when he doesn't even know what you do about the condition of things ;) ...J.D.
 
1 - 7 of 7 Posts
Top