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Complete rebuild 4G64 SOHC only 50psi in cylinder 1?

1097 Views 15 Replies 4 Participants Last post by  Leadfoot6
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?
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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.
"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.
@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.
Well, if all you need is a lifter while you were doing all the writing about this you could have had it fixed. ...J.D.
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.
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.
Update, in case anyone finds this post, as well as a further question. YES, 4 months have passed and I and still F%#$# around with this car.
I found the issue, this is after towing the car to the "Engineer" that sold me a rebuilt head and rebuild the bottom end for me. Then waiting 3 months for him to "Take a look" where he said. "Yeah, you need to take the head off" before towing it back to my house.
Head came off and went back to the "engineer" where he said I had bent 2 inlet valves. I showed him pictures of the completely unmarked piston. and he gave me the head back with "new inlet valves".
Put it back on and guess, what? compression had bumped up to 70psi, still not great, but a change.
I started playing around with different lifters under the inlet and exhaust rockers and started seeing small differences when playing on the exhaust side. Removed the exhaust rocker and 175 like the rest.
It turns out one of the exhaust valves is about 1mm taller than the rest. I used a metal ruler to prove it. This is after I have returned the head once already complaining about that specific cylinder!
The "Engineer" says he is ordering me a 40 thou shorter lifter which will fix it.
My questions now are:
1) Does this "Engineer" know anything about cylinder heads even though this is his entire business?
2) Should I be worried that the valve seat is messed up and pulling into the head, causing this, The car needs to run for at least 3 years. Especially after a full engine rebuild!
3) Is it standard practice to grind the valves to the correct heights on these heads, and they forgot to do this one?
4) Nowhere in any of the manuals I can find any mention of different length lifters, so once again WTF?

All the towing, new head gaskets etc have all been at my expense so far as well. Starting to get slightly pissed off here and wondering if I should get a head from somewhere else.
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Where in Australia are you located?

Or, more importantly, where is the mechanic located?
Located in Brisbane.
And it seems the valve stem projection measurement is incorrect. I am not sure if the seats have been done on this head. Really can't trust what else is incorrect if he is finding "bent valves" and doesn't know how to measure the specs of a cylinder head.
This listing:


seems to suit your ZE Outlander.
Thanks, I have unfortunately found a few other people that have been burned by this specific business and are currently in a legal process with the owner. IMO, it seems like his business is going under and I just happen to catch it at the wrong time.
So New head it is, Throw more $$ the problem!
Thanks, I have unfortunately found a few other people that have been burned by this specific business and are currently in a legal process with the owner. IMO, it seems like his business is going under and I just happen to catch it at the wrong time.
So New head it is, Throw more $$ the problem!
It seems that you have answered your own earlier question(s)

P.S. I have not had any dealings with the cylinder head supplier I linked to above.

I am unable to supply advice, for or against, that particular supplier.

Let us all know how you get on with this problem.

I hope it works out for you.
Update, in case anyone finds this post, as well as a further question. YES, 4 months have passed and I and still F%#$# around with this car.
I found the issue, this is after towing the car to the "Engineer" that sold me a rebuilt head and rebuild the bottom end for me. Then waiting 3 months for him to "Take a look" where he said. "Yeah, you need to take the head off" before towing it back to my house.
Head came off and went back to the "engineer" where he said I had bent 2 inlet valves. I showed him pictures of the completely unmarked piston. and he gave me the head back with "new inlet valves".
Put it back on and guess, what? compression had bumped up to 70psi, still not great, but a change.
I started playing around with different lifters under the inlet and exhaust rockers and started seeing small differences when playing on the exhaust side. Removed the exhaust rocker and 175 like the rest.
It turns out one of the exhaust valves is about 1mm taller than the rest. I used a metal ruler to prove it. This is after I have returned the head once already complaining about that specific cylinder!
The "Engineer" says he is ordering me a 40 thou shorter lifter which will fix it.
My questions now are:
1) Does this "Engineer" know anything about cylinder heads even though this is his entire business?
2) Should I be worried that the valve seat is messed up and pulling into the head, causing this, The car needs to run for at least 3 years. Especially after a full engine rebuild!
3) Is it standard practice to grind the valves to the correct heights on these heads, and they forgot to do this one?
4) Nowhere in any of the manuals I can find any mention of different length lifters, so once again WTF?

All the towing, new head gaskets etc have all been at my expense so far as well. Starting to get slightly pissed off here and wondering if I should get a head from somewhere else.
Question: did you remove the head or heads? Was the motor/engine still in the car?. Correct me if I'm wrong --Weare talking about the V6 engine, correct?
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