98 3.1L top end rebuild (pics)

[kevinb70]

Well I got the intakes back from the shop. They did a great job getting the inside of the upper manifold clean of all carbon buildup.

Paint/Prep I used. Couple light layers of adhesion promoter followed by black and silver. Didn't need hi heat on the manifold but I wanted an exact silver match with the rest of the parts I painted.

Silver detail. I sprayed silver in a 2-liter bottle cap and used a small brush. Hold the brush horizontally so you only paint the very top of the lettering and lines.

I masked the upper then started with some light coats, after spraying 1 coat, I would continue masking the lower in between coats. Then I went back and forth painting a light coat on each piece, allowing drying time between coats to prevent runs.

Might actually have time to assemble this weekend

[jeranamo]

Looks good man. Did you end up supporting the engine with a jack when you took off the top motor mounts to do the heads? I've taken both of those off before without even supporting the engine... is it really that bad to do? The lower mounts are still connected obviously. Did you have to remove any of the lower mounts to get the heads off? Thanks in advance.

[kevinb70]

yup, soft wood on top of a hydraulic jack to gently support the engine. i dont like supporting the weight of the engine on the oil pan, but it is a rigid honey-comb reinforced aluminum pan.

you have to remove the engine mounts from the heads. the right mount is just bolted to the side of the head, the left mount sits on the leftmost head bolt round stud.

so yes, both engine mounts must be removed in order to remove the heads.


you will have to loosen (not remove) two bolts on the a/c compressor. with the compressor a bit loose, you can wiggle the engine mount out.


another way to hold the engine up, is to have it in park, roll the car back a tad. This will pull the engine vertical. Then make sure the wheels can't move and hold the engine in position

[jeranamo]

Are the only ones you removed the ones that attach to the upper dogbones? Those are the ones I've completely removed before with no support underneath... did I mess my axles or trans up by doing this? I assumed there were lower mounts that held it in place as well... I hope i didnt crush anything...

[kevinb70]

only removed the uppers.

your transmission in park is what held the engine up. no you didn't harm it.

[jeranamo]

Even if I had the trans in neutral? I guess I'm just confused why its necessary to support the bottom of the engine. When i've done plugs before I've removed both dogbones and pulled the engine forward and not even attaching straps till after theyve been removed.

[kevinb70]

im surprised it stayed in position then... maybe the bottom mount is tight enough to keep the engine from tilting when you remove the uppers. mine needed to be supported a little bit from the bottom

[jeranamo]

Hehe, now you see why I am nervous that I may have crushed something. Oh well... hopefully that is not the case. I will definitely hold it in place with a jack now that I know. Thanks a lot for clearing that up.

[kevinb70]

started assembly on 3/20. cranked engine a good bit (without spark plugs installed) to prime the oil pump and get oil circulating thru the engine.

[jeranamo]

Wow, thanks for posting all the pictures. This will really help out when it comes time to reassemble mine. Is it okay to clean the heads and springs with engine degreaser?

[kevinb70]

was househunting today so nothing was accomplished on the car.

ya degreaser is fine.

if you are cleaning parts by hand ... the heads are going to take alot of time - especially the runners. you won't be doing much for the valves and seats unless you take the valves out.

since the 3.1L has an egr, puts alot of carbon in the the upper manifold, which is very difficult to clean by hand.

TB cleaner would work the best on the carbon. if you blast, i would use soda over traditional abrasives.

machine shop cleaned and rebuilt my heads, and cleaned/blasted my upper/lower intake... those along with valve covers, i'd let a machine shop clean them, or it will take you hours.

exhaust manifolds, heat shields, brackets, bolts, throttle body clean up easy enough.

rockers/pushrods/lifters clean up easy and i would never take them to a shop for cleaning b/c of the chance of them getting mixed up. I had them all bagged and tagged so there was no mixup, and i only worked with one bag at a time, and still reverified that the 1st, 4th, and 6th push rod was the longer (exhaust) when reinstalling. i used diesel with brass brushes and those round bottle brushes

i picked up a couple of fittings for a pump i have, I am going to cut in half my old lower rad hose, then connect fittings to garden hose, connect 1 hose to water pump, other to lower rad outlet. then run the pump to circulate water in 1 bucket and hopefully get trash to settle in the bucket.

then ill pump clean distilled water from one bucket into the engine, and at the lower rad is a hose leading into a discharge bucket.

ill remove the thermostat and use this to flush the remaining traces of dexcool and sludge, remains of leak fix, etc.

[kevinb70]

Got some fittings for a pump I have and made a coolant flush machine.

Hoping to get all the sludge and crud out of the block and radiator.

Thermostat will be removed.

The filter is a plastic jug with holes cut, wrapped with nylon screen, stapled together.

Hopefully can get this to run unattended for a couple hours. I've got some steel spikes to put in the jug to keep it from floating.

The white pvc parts will be connected to 1/2 of the old rad hose.

Pump inlet hose in bucket of distilled water pushes water into the water pump inlet.

Water then circulates thru the block, pushing out any trash and old dexcool.

Water goes thru the rad, and out the lower rad outlet. this goes into the bucket to fill it up. Once this bucket has filled up some, I swap the intake hose to this bucket and circulate water, hopefully getting sediment to stay in the bucket.

Then I'll drain the system, blow air thru to get water out.

Then refill with coolant and distilled water.

I can flush the heater core separately.

[jeranamo]

I have a question regarding the rear head. You show a picture where you have connected the exhaust manifold to the head prior to installation. Does this mean the head can be pulled out with the exhaust manifold still attached or will doing so just make it impossible to remove the bolts?

[kevinb70]

Originally Posted by jeranamo

I have a question regarding the rear head. You show a picture where you have connected the exhaust manifold to the head prior to installation. Does this mean the head can be pulled out with the exhaust manifold still attached or will doing so just make it impossible to remove the bolts?

yup you can remove the head with the exhaust manifold and heat shields attached, and install them attached, too.

it is an advantage to have your exhaust manifold torqued correctly, off the car.

[jeranamo]

do you have to get under the car to access the exhaust manifold nuts/bolts or is that just necessary for removal of the pipe? doesn't look like there is much room to get at exhaust manifold area from under the car. I've got the intake manifolds off but I want to pull the heads off too just to be safe.