intake manifold gasket procedure available?

[ggomez2]

Hello,

I've been needing to do the intake manifold gaskets for my 94 4.0l Ranger for a few years now. I am planning on tackling this work this weekend but I cannot find a write up or a how-to for this. I'm a bit confused regarding the need to remove valve covers, and the issue with the fuel rail removal.
Any help including where to buy the gaskets would be great.

 

[Maniak]

I don't think I"ve seen a writeup on it here .. But, here are some tips/info.

I'm assuming you fixing a lower intake leak

The Valve covers actually bolt to the lower intake, so that is why they come off.

The fuel rail is between the upper intake and the lower intake. Take the upper intake (plenum) off by removing the nuts that are holding it on..

LEAVE the fuel rail connected to the lower intake. Remove the bolts that hold the lower intake to the block/heads.

Take the fuel lines off slowly, there is pressure there unless you relieve the pressure. One trick is to disconnect the inertia switch, start the truck and let it stall. That should relieve the pressure. Other people just let it leak as they loosen the fuel lines or use a fuel pressure testing gauge to relieve the pressure.


~Mark

 

[RangerX]

I used this link: http://rockledge.home.comcast.net/~rockledge/RangerPictureGallery/40LIntakeGasketReplacement.pdf

 

[konstan]

Here are some pics

http://www.explorerforum.com/forums/showthread.php?t=243297

As for the step by step procedure, the one in the chilton book was good enough as far as I can remember... it was very straightforward -- disconnect everything, remove the valve cover, remove the upper intake, remove the lower intake

USE NEW good quality valve cover gaskets or it will leak
USE locktite on the valve cover bolts or it will leak
Use the new lower intake gasket, obviously

 

[Tony H]

The valve covers on these engines overlap over the intake. It's an odd design.
That's why the covers have to come off.
Leave the fuele lines attached. When it's all loose, lift it and rock over to rest on the Brake Master Cylinder.
The hardware is torqued to only 18 ft lbs.
When the Intake is removed, you will see the leak. More then likely it's at the water jacket right there next to the Temp Sender.

The biggest pain is unclipping the harnesses from their mounting and marking all the connectors.
Slow and easy will get you through it if this is your first time.
Teh fuel rail is not a tubular rail, it is a machined piece of aluminum. It actually makes life easier then a tubular rail.

 

[ggomez2]

Thanks to you both for your replies.. any suggestions on how to clean the metal surfaces the gasket sits on?
RangerX, the pdf you suggested is for a '97 Ranger; any differences for the 94 I have?
Any suggestions on how to clean the grime/oil/dirt I'm sure to find once I remove the valve covers, intake manifolds, etc?
18 ft /lbs or 18 in/lbs?
Plan on doing this Saturday and Sunday if it takes me that long. So wish me luck!

 

[RangerX]

RangerX, the pdf you suggested is for a '97 Ranger; any differences for the 94 I have?
Any suggestions on how to clean the grime/oil/dirt I'm sure to find once I remove the valve covers, intake manifolds, etc?

Mine's a 93, and the only difference I (vaguely) recall is my EGR was slightly different, but I think that was it. I printed out that whole PDF and had it under the hood with us. I had help (90Ranajo) who had engine teardown experience, so I was really just the helper.
We followed and trusted the printout, it's very well written. I bought the gaskets he recommends at the end. We did not remove the hood. I scrubbed the valve covers inside and out with solvent. The intake was really built up with crap inside, but instead of trying to clean it by hand, we ran some Seafoam through when we had it back together.
I think it took us 7 or 8 hours, we finished at sunset.

 

[ggomez2]

Standard sockets or were there any torx headed bolts?

 

[konstan]

Thanks to you both for your replies.. any suggestions on how to clean the metal surfaces the gasket sits on?

There is a "gasket remover" spray, its comes in a metallic green can. NASTY stuff if you get it on your skin or on paint or on anything, but clears the old gasket crud by literally melting it off...

Most people say not to use metal scrapers because they can score gouges in the mating surfaces that will result in leaks.

A lot of people would also say not to sand the mating surfaces.

I have had good results with light sanding (fine sandpaper) as long as you do it lightly and vary the pattern. I believe that it creates a good surface to seal against the gasket. I think that is better than risking leaving residual material from an old gasket, which might stick out 0.5mm and present an UNEVEN surface to the new gasket and the mated part. Sand evenly, lightly and carefully and you will have nice mating surface... to me doing that just "feels right"...

 

[ggomez2]

Thanks to everyone for the input! Finished up Sunday mid-afternoon; truck runs great, no leaks. Other than a couple of missing bolts in the valve cover (lost one, broke one), pretty straight forward. I surprised how clean the valve train/covers looked. Intake manifold ports were all pretty nasty but used carb cleaner to get it all clean.
Odd issue though, not big a deal but it is bugging me: the max A/C doesn't seem to work. It blows air, but I believe it's not blowing as hard as it used to. I know before the gasket work I did, if it was in MAX A/C and the truck was under load (uphill, lugging engine, etc), the vent air would slow down as if it was reverting to panel all on its own.
Any ideas?

 

[Tony H]

It blows air, but I believe it's not blowing as hard as it used to. I know before the gasket work I did, if it was in MAX A/C and the truck was under load (uphill, lugging engine, etc), the vent air would slow down as if it was reverting to panel all on its own.
Any ideas?

Check for cracks in your vacuum hoses. You just pulled them all off and moved stuff around , Vacuum controls the Vent doors, so it makes sense that you may be leaking somewhere.

 

[ggomez2]

I only came across two smaller vacuum lines, both start from the top and back of the intake manifold / throttle body. They route all the way over to the passenger side of the truck: one to a black box which is where the blower is, I believe; the 2nd goes to some sort of small, metallic cylinder which is attached to the fuel rail.

I tested the lines when they were disconnected and they seem to hold pressure. The only other vacuum related hose I came across was the one that goes to the brake cylinder.

Any other thoughts on what to look for?

 

[Tony H]

Make sure all the unused nipples on the intake manifold vacuum 'tree' have rubber caps on them.
The get dry and fall off or crack.
Yes you may only have 3 vacuum lines coming off tha tree but there should be Caps on the unused nipples.