View Full Version : It's time to tear into her!!

07-02-04, 12:12 PM
Today I tore into my 94 STS motor I have at my shop a bit. I took off everything down to the head/cams. Everything on the top is off, intake/fuel rail/injectors, valve covers, starter, plugs/wires and all.

My question to you guys is, how far should I take my "rebuild" with the motor only having about 80K on it. I want it to be refreshed, clean and ready to roll but not sure if a complete rebuild is nesessary. So I figured I would talk to the people that would know best. YOU GUYS! :) Ill post a few pics of what she looks like currently.

Also I am not looking to spend more than say $500 on this, so I'm guessing that would include the following....
-Full gasket set
-getting electric water pump so I know that was on the tip of your tougne! lol


07-02-04, 12:20 PM




07-02-04, 10:24 PM
Do you have the timesert kit?
If not, there's $350 gone just to bolt the heads back on.
I think the head gaskets plus all others needed to do the job cost me around $150.
If you already have the kit then you have some extra cash to throw at extras.
Some one better versed than I will pick up from here, I'm sure and explain about the bottom end being pretty solid.

Have fun,

07-02-04, 11:07 PM
Uh...who told you that was a 94 model engine??? 95 and later model engines had the plastic, one piece intake manifolds. Yours is a 95 or later engine..... 93/94 had the large diecast magnesium box type intake with the silver cover acting as the actual top of the intake manifold with the plastic tuning tubes inside. What is in the pictures is a one piece plastic intake, not the 93/94 style of intake manifold.

Not that it really matters...but...if you can't believe the year you were told what can you believe about it's history.....???

I guess it depends on what you know for sure about the engine....do you just know that it has 80K on it?? Or was it a know good running engine???

Personally, given the swap that you are intending I would take the heads off, timesert the block for insurance and replace the head gaskets. If the bottom end looks dry I would tend to leave it alone ...but...taking the pan off might be a good idea just to see what is in there in terms of oil residue and debris. Cut the oil filter that was on the engine apart with a large pipe cutter and examine the paper filter media to see if there is any evidence of bearing or other debris that might indicate an impending problem. It would be a good idea to replace all the rod and main bearings and reseal the lower end for security but that would eat up more than 500 in bearings probably....and you CANNOT take the rod bearing caps off for inspection and then reuse the rod bearings. If you take the rod bearing caps off then the rod bearings MUST be replaced or they will fail later. The rod bearings in particular are a one use deal. So...given the expense of opening up the lower end I would limit it to inspecting the oil filter and removing and reinstalling the pan for inspection...unless you see something nasty in the process.

The heads certainly do not need reworking at all nor the timing drive or chains or oil pump or anything. The head gaskets would be the only insurance item and I would honestly be tempted to just leave them alone if you have assurance that the engine was running fine when you bought it.

07-03-04, 12:55 PM
Well SHIT, see this is why I leave my motor stuff up to you guys!! Now I'm gonna start diggin a little more on the history of this thing. Will the dealership be able to tell me a year of the motor by the engine number code?
I'm gonna stick to the pan inspection and put the topend back together
BBoB you da man

07-04-04, 03:47 PM
Are there certain code numbers that tell what year the motor is?

07-07-04, 12:38 AM

07-07-04, 01:19 AM
<shrug> On mine, there was a year stamped into the water manifold casting...

07-07-04, 01:49 AM
If it were me I would timesert the block and do head gaskets if you are into it this far. It might save some time and agravation to do it now with the engine out.

07-07-04, 03:11 AM
I'm not a engine guru but wouldnt it be good to check out the oil pump if you choose to check the oil pan area and all.

07-07-04, 11:37 AM
I would do the timeserts on the block while you have it apart this far. Much easier than after it's in a car. Maybe you can get a used timesert kit and resell it when you are done. Won't cost much that way.

07-08-04, 12:00 AM
I'm not a engine guru but wouldnt it be good to check out the oil pump if you choose to check the oil pan area and all.

Uh...the oil pump is on the end of the crank in a Northstar and NOT in the oil pan area. It is accessed by the front cover of the engine and is immediately behind the harmonic damper on the crank.

The Northstar oil pump is very robust and should never need replacement. That is the last thing that I would consider replacing on a used engine. The pump is a gerotor style pump that just doesn't wear or need replacement like the oil pumps of yesteryear.