Hello I have a 20V 4AGe black top that I have in the car and found out it has low compression on cylinder 3...
1- 150
2 - 180
3 - 60 (with oil test and no oil it'll be at "30")
4 - 150


I want to rebuild it... How do i rebuild it? Is there a guide? This is my first time doing something like this ..

You can down load the repair manual here. Search pbase.com/paulgreen/image/38984465
davew7

with only a small jump after adding oil, I'd say you have a valve problem on cyl 3. Most often it will be a burnt, or bent exhaust valve[s].

davew7 wrote:You can down load the repair manual here. Search pbase.com/paulgreen/image/38984465
davew7

Cannot find? it says invalid

oldeskewltoy wrote:with only a small jump after adding oil, I'd say you have a valve problem on cyl 3. Most often it will be a burnt, or bent exhaust valve[s].

What do you suggest I do if it's a burnt / bent exhaust valve?

Do you think piston rings are okay?
I never rebuilt an engine before..

Manual?
"Cannot find? it says invalid" That is very possible since I down loaded the manual about 15yrs ago. The only other ID is that the manual was release in 1997 and is manual MT2001.
davew7

Blacktop engine manual - https://locost7.info/files/engine/4age_ ... bt4-em.pdf

All the Blacktop manuals - https://locost7.info/mirror/4age_blacktop.php

You wont know until you tear the engine down. Before you order any parts - it it best to get the engine dismantled so you can carefully inspect it - then determine what is needed to fix it.


Where are you??

oldeskewltoy wrote:Blacktop engine manual - https://locost7.info/files/engine/4age_ ... bt4-em.pdf

All the Blacktop manuals - https://locost7.info/mirror/4age_blacktop.php

You wont know until you tear the engine down. Before you order any parts - it it best to get the engine dismantled so you can carefully inspect it - then determine what is needed to fix it.


Where are you??

I am in Los Angeles actually

davew7 wrote:Manual?
"Cannot find? it says invalid" That is very possible since I down loaded the manual about 15yrs ago. The only other ID is that the manual was release in 1997 and is manual MT2001.
davew7

MT2001? Is that the name? can you send me a copy of the manual?

This link... https://locost7.info/files/engine/4age_ ... bt4-em.pdf contains all
the information you need for an engine teardown. It is one of the links from locost
given above and you should at least browse all the links so you can get an overview
of how the engine works.

When taking the engine apart have a supply of ziplock bags and a sharpie on standby.
Bag and label all the small parts and bolts/nuts so you can remember where they came
from. Take pictures of hoses and electrical connectors as you go so that when the time
comes to re-assemble the engine you can get them hooked up correctly.

Clean everything and inspect parts for damage or wear as you remove them.

If dismantle the head make sure all the parts are clearly marked so that they can go
back in the same hole that they came out of. If you dismantle the block not only do
you need to make sure that you know which hole the parts come out of, but also which
way they were facing. Rod bearing caps are matched to the rods and main caps are
matched to the block. Do not mix and match.

If the head needs work I recommend that you take the complete assembled head to the
machine shop and let them remove the cams and valves. Likewise, if the block needs
work, take the assembled shortblock to the machine shop. They have all the tools and
all the measuring equipment to do what is required and hand you back an assembled
piece that you can install without worrying about... did I get the torque settings right...
or... are the seals sitting right... or... did I forget something ? Good luck

Cheers... jondee86