Write-up: Chasing a coolant leak (Replace LIM gasket)

[MaioCampo]

Hey,

I used a couple of threads to help me with my LIM gasket replacement. I also used the Chilton manual. Each were valuable to me, so I here present my own notes on the job.

First, my problem was a coolant leak that appeared to be coming from somewhere behind the AC compressor. The thermostat housing, upper heater hose, and freezer plug were all checked and none appeared to be the culprit.

Thermostat and hoses are pretty easy, but for those wondering about the freeze plug see the following thread: http://www.explorerforum.com/forums/showthread.php?t=301245&highlight=freeze+plug

The two threads I used to help me with the LIM gasket replacement are:

http://www.explorerforum.com/forums/showthread.php?t=384221&highlight=LIM (opening post has another link to documentation that I printed out)

http://www.explorerforum.com/forums/showthread.php?t=307425&highlight=LIM (very good descriptions with photos)

I like checklists, so here is my write-up in a checklist fashion. As with everything, each vehicle will be different, and folks will want to do things their own way. As a rookie I was afraid of this job, but it was really easy. Take your time, read several threads, get the steps straight in your head, and then jump in, taking lots of photos and bringing all questions here.

Here we go:

[ ] Disconnect battery negative
[ ] Disconnect inertia switch (under carpet, under passenger side dash)
[ ] Remove gas cap to relieve pressure
[ ] Attempt to start engine (should not start)
[ ] Remove air intake duct
[ ] Drain coolant
[ ] Remove belt (Tensioner - 16mm)
[ ] Unplug Alternator (3 plugs)

[ ] Green - Top
[ ] White - Middle
[ ] Red - Bottom (remove cover, then remove 10mm nut)​

[ ] Remove Alternator (3 bolts - 13mm)
[ ] Remove upper radiator hose
[ ] Remove throttle cable (red; gently pry off with small flathead)
[ ] Remove throttle cable bracket from upper manifold (2 bolts - 10mm)
[ ] Unplug TPS (throttle body; big/wide; red/black inside)
[ ] Remove throttle body (4 bolts - 8mm) * I replaced gasket

[ ] Remove vacuum line from throttle body​

[ ] Unplug IAC (small; red & black; orange inside)
[ ] Remove IAC (2 bolts - 10mm) * I replaced gasket
[ ] Unplug IAT (round; white)
[ ] Remove bolt from top of upper intake holding vacuum line (10mm)
[ ] All vacuum hoses from vacuum tree at back of upper intake

[ ] Picture (either take a digital pic, or draw one)​

[ ] Remove spark plug wires from coil

[ ] Note position of all wires​

[ ] Unplug coil pack (wide)
[ ] Remove coil pack (2 bolts - 13mm; 1 bolt - 17mm)

[ ] Remove cylinder looking part attached to coil (unplug, or 6mm bolt)​

[ ] Remove upper intake manifold (6 nuts - 13mm)
[ ] Remove upper heater hose
[ ] Unplug canister purge valve (looks like cylinder; connected to vacuum line to throttle body)
[ ] Remove fuel rail connections (wear safety goggles; open garage; prepare for fuel)

[ ] Front fuel line - attached to fuel pressure regulator - (17mm wrench)
[ ] Vacuum line - attached to fuel pressure regulator
[ ] Back fuel line - attached to fuel rail - (adjustable wrench)
[ ] Unplug fuel injectors (6x - note position, wire length should make it obvious)​

[ ] Unplug 2 plugs at far back of engine (1 passenger side; 1 driver's side)
[ ] Remove harness to left (wire to water pump remains)
[ ] Remove studs from fuel rail (6 studs - E7 external torx socket)
[ ] Carefully disengage fuel rail assemby from injectors by lifting and rocking rail (Chilton)
[ ] Remove fuel injectors from lower intake manifold by lifting and gently rocking (Chilton)
[ ] Unplug temperature sending unit (small elbow connector near/under thermostat housing)
[ ] Unplug ECT sensor (round harness to right of thermostat housing)
[ ] Use zip ties to keep wire harnesses out of way (open up space directly above valve covers)
[ ] Remove valve cover gaskets (8 bolts/per cover - 10mm)
[ ] Remove lower intake manifold (6 bolts - 10mm; 2 nuts - 13mm)

* Be careful if you remove the fuel rail. While lifting I lost grip and the rail slapped back down onto the LIM and broke a fuel injector.

Reassembly notes:

* Gasket Kit - FEL-PRO MS98005T

* Place rag in valley to prevent material from dropping in
* Take time to clean all mating surfaces on lower intake, fuel rail, valve covers, and upper intake.
* Clean all nuts and bolts

* Remove and inspect rockers (3 bolts/per side - 15mm)
* Per Chilton, loosen outside to inside, one/two turns at a time
*Attach rocker arm assembly

[ ] 15 ft lbs
[ ] 25 ft lbs
[ ] 40 ft lbs
[ ] 50 ft lbs
* Per Chilton tighten outside to inside, one/two turns at a time
​

* Install two-part LIM gasket

[ ] Clean mating surfaces
[ ] Tabs over each port.
[ ] RTV surface between sides (flat surface between valley sides). Extra bit at corners.
​

* Attach LIM (immediately after applying RTV)

[ ] 18 ft lbs (per Chilton) - two turns at a time
[ ] Cross pattern - corners then inners
​

* Install fuel rail (Chilton)

[ ] Lubricate all injector o-rings with clean engine oil
[ ] Install injectors into fuel rail using light twisting/pushing motion
[ ] Clean LIM and fuel rail mating surfaces
[ ] Position new fuel rail gasket to LIM
[ ] Carefully install fuel rail assembly to LIM. Make certain to correctly position injector insulators (plugs).
[ ] Push down on the fuel rail to make sure o-rings are seated
[ ] Hold fuel rail in place and install retaining studs finger tight
[ ] Tighten studs to specification (6 to 7 ft lbs - Haynes) - Use cross pattern
[ ] Connect front fuel line to fuel pressure regulator
[ ] Connect rear fuel line to fuel rail
[ ] Attach vacuum line to fuel pressure regulator
[ ] Connect the fuel injector wiring harness at injectors​

* Install valve cover gaskets and covers

[ ] Clean all mating surfaces
[ ] RTV at LIM seam
[ ] Position new valve cover gasket (make sure right-side up)
[ ] Install bolts & nut finger tight
[ ] Tighten nut and bolts (3 to 5 ft lbs) - Use cross pattern​

* I left thermostat housing on throughout the gasket replacement, but later found the LIM holes to be stripped. Used Helicoil tool to fix all three holes, then reattached housing to LIM before installing. 3x 10mm bolts - 7 ft lbs.

* Be careful with lines connected to canister purge valve. The valve connectors can be brittle, and break easily.

* Install upper manifold gasket

[ ] Clean all mating surfaces - fuel rail and upper intake
[ ] Position new fuel rail gasket on top of fuel rail
[ ] Install 6 nuts finger tight
[ ] Tighten 6 nuts in cross pattern (Haynes)

[ ] 6 ft lbs
[ ] 12 ft lbs
[ ] 16 ft lbs​

* Take time with reassembly. Take in stages (LIM, Fuel Rail, Valve Covers, UIM). At each stage clean, assemble, then check all connections (vacuum & electrical).

* Bring all questions here. Bring all questions here. Bring all questions here.

Hopefully that helps someone.

 

[malohnes]

Nice and detailed write up. I prefer pictorial versions, but this is nice to go hand in hand with pictures. Among other things, it is write-ups like this that make this forum so good. Folks of all levels sharing info and keeping our truck alive and well.

 

[MaioCampo]

I prefer pictorial versions, but this is nice to go hand in hand with pictures.

I'm a picture man as well. Heh.

This list is pretty much yours. I printed it up and added notes as I went along. As much as I like pictures I actually used those times when I needed one as a chance to step away (I'm a big fan of stepping back), refer to your thread and the other I have listed here, then go back out to the garage and my list and hit it some more.

Another organization step I took, besides the checklist, I got me some of those disposable refrigerator containers and put all nuts and bolts in each, along with notes on where they came from, how many there were, and size. When all was done I had all empty containers.

 

[Sonofbumperbolt]

Nice check list. Well done.

 

[shamal]

Very Nice checklist, well done, going to save me a ton of time ! Thank you for your efforts and discipline !

 

[FR-425]

Copy; Paste; Print;. ..... .. .. ..Nice!

I'll bet his LIM is all done leaking, for say 20 years!

 

[MaioCampo]

I hope so! 3 months and counting, not a problem. Woohoo!

 

[shamal]

Does anyone have any thoughts on injectors, while we are in there? Clean and replace the O rings, some thoughts on this site re they are meant to last a long time, and if working leave them alone, and they seem to be working fine.
Am also considering changing the rockers and rods, Delta Cam is out of rods, can do the rockers , he says to buy a rod set from NAPA. Thinking of changing the fuel pressure regulator while in there. So far best online for me has been Rockauto, considering getting gaskets, etc there.
Thanks again for all the great info, we will photo and add to this thread for subsequent users.

 

[FR-425]

Give this a ready poo:

http://www.e30tech.com/forum/showthread.php?t=85631

Here's the rebuilt kit:

http://www.ebay.com/itm/V6-4-0-Ford...Kit-ORings-Filters-Caps-CSKBO36-/190805299054

 

[shamal]

FR-425 : You're a good man, I very much appreciate all your efforts and posts. Thank you for taking the time to post 2 links, these 2 are VERY helpful.
Take Care

 

[FR-425]

 

[shamal]

Injectors back from Mr Injector

I sent mine out to Mr Injector, and got them back, He does a superb job, they look brand new, and cost $15 each to service.
I've been cleaning and scrubbing for a about 2 days worth of work, dong the engine bay and all the parts. Removed the A/C and found a replacement air box at the scrap yard. I have lots of pics to post when we re-install everything, tomorrow I hope.
In the attached pdf are the test results before and after servicing the injectors. Also in the notes at the bottom of the page you will see his instructions on installing the injectors, specifically noting to install them in the fuel rail 1st, and then install the rail to the LIM.

 

[shamal]

Leaking LIM Before

This is an attempt to add pictures to the excellent write up and checklist, as well as the 2 other threads noted at the start, by maiocampo.
This is a '93 Canadian 4X4 project, with leaking LIM gasket, needing removal of AC (never used), injector servicing, rocker and rod replacement, and replacing any parts that are suspect and general cleanup ( by dad ) to include a few more new parts than would normally be done by most.
This project is a learning experience for my 2 boys, a father / son deal than goes well beyond the necessary to give them the opportunity to experience a wide variety of tasks and skills.
Hopefully it will encourage others to tackle the jobs done here, who might have otherwise hesitated.
Rockauto was used a parts source as much as possible, Delta Cam for the rockers, Mr Injector serviced the injectors.

 

[shamal]

In the previous post I am pointing at the bolt holding the distributor on, that needs to be sprayed before hand to loosen it up, this can be a tight one to get out.
This sequence shows the UIM electrical connections, alternator and AC removal. You can see the throttle connections removed here, by popping it off with a flat blade screw driver.
The schraeder valve was used to take the fuel pressure off.

 

[shamal]

The LEAK and UIM removal

It is hard to see the leak location, and we 1st saw it while removing the AC compressor etc and lines, and the upper rad hose.
You can see the dirt etc that needs a vaccum before you pull the UIM, and I've included some detail on the fuel pressure connection lines.

 

[shamal]

Fuel Rail

Underside of UIM shows gasket in excellent condition, and a pic of that front nut on the UIM
Careful with the injector plugs they are brittle after all these years, especially the clips that lock them onto the injector.
You can see the fuel rail studs being removed, the dirt that accumulates on top, that needs to be cleaned off

 

[shamal]

Fuel Rail

Here is the fuel rail, you can see some injectors stay on the rail, some on the LIM, As noted by others, you can remove the LIM with the fuel rail still on it.
Note the dirt on the injectors, and how clean the front of the rail stays compared with the back.
Some of the O-rings stay in the rail when you CAREFULLY remove the injectors from the rail. These are going for service.

 

[shamal]

LIM removal

Here you can see the bolts being removed from the LIM and the Infamous Leak !!
This is the area that is hard to see with the engine intact, and once exposed you can see why the leak occurs, the intersection of the LIM, engine block and the valve covers

 

[shamal]

Underside of LIM and Valve Covers

Here is the underside of the LIM, more detail on the leak corner, it's gasket and we found a leaking valve cover gasket as well. I always thought I had an oil pan gasket leak, turns out it was coming from up here. As well the antifreeze has corroded the valve cover lower rail.
The pushrods were really worn, as were the rocker contact points. The oil was changed on this vehicle every 5 K. We bought it used in '96, so who knows what the history was before then. pretty dirty in there huh ?
OK now to pull the AC off the firewall.

 

[shamal]

AC removal

Here is the firewall with the AC unit removed. I had gone to the scrap yard and got a replacement box from a Ranger for $5.
There is 1 nut inside the cab, below the glove box, all the rest are on the firewall, and pretty accessible. I removed the fan motor 1st, much easier this way.
My injectors are back from Idaho, Mr Injector ( $95 ). I have included the report that comes with them, and you will see they were working fine when tested before servicing. You will also see instructions on how to install the new injectors, especially the part on placing them in the fuel rail 1st.