[Bosnian Discovery]

Car is a 2003 Disco SE with 110K miles. Bought it in July 2011 with 77K miles and it's been near rock solid ever since with nothing but fluid changes and minor replacement parts. However I've been collecting parts for a year to do the timing cover rebuild and fix some leaks, and this past weekend I was finally able to get started.

I had no intention of doing the work until I got some free time around the holidays, but last Monday I noticed a pinhole coolant leak coming from the plastic distribution fitting on the lower coolant hose. Wasn't serious so I ordered the part and kept driving. Then on my drive to work Wednesday morning I notice my battery light start blinking and my voltage start to vary wildly, between 11.9-17.1! Turned it around immediately, parked it and planned to start work early Saturday.

I've been dealing with seeping oil pan and timing cover gaskets, and I was pretty sure my front crank seal was gone too, judging by the amount of caked on oil around my timing cover. I figured if I was going to do something I may as well do it right, so I decided to tear all the front end parts off and replace everything - ending with the oil pump gears. I even managed to pull my leaky steering box and rebuild the top plate with new gaskets. I thought it was going to be an absolute bear of a job to get it out, but it only took maybe 30 minutes!

Below are some pictures of the process.

Acessories removed, notice the filthy timing cover for years of leaking:



Closeup:



The culprit:



The parts, cleaned and organized:



Rebuilding the pulleys using high quality Nachi Japanese bearings. #6203 for the smaller pulley and #6304 for the larger pully are in fact the right numbers. Only needed some snap-ring pliers and a bench vise for removal and installation of the bearings - quite easy.





I guess I should consider myself lucky - the oil pump ring gear came out in three pieces. It still managed to keep the pressure high enough because god knows how long i've been driving like this, but maybe this would explain my intermittent lifter noise during startup.



With the cover off I also noticed a lot of slack in the timing gears and chain, so I'll be replacing those too - cheap and easy. I'm also going to take this opportunity to do what I've wanted to for a long time on this car - install an oil pressure gauge and convert the ancient clutch fan design to a modern electric thermostatically controlled fan. It will run cooler, the engine won't have as much rotating mass attached to it, and I'll have lots more room to work under the hood. I'll post a write-up as I go along.

The purpose of this post was to show a bit of my handy work but also prove to some guys that are hesitant about doing their own teardown that it really is a pretty straightforward job - frankly it's one of the easiest "major" jobs I've ever undertaken on any car. The only "specialty" tools you need are the fan clutch removal tool (or use a crescent wrench) and a breaker bar with a 15/16 socket to remove the crank pulley. That's it. Everything came apart easy and the only struggle was removing the damned paper gasket on the water pump which had burned itself to the aluminum sealing surface.

Sorry for the long post and thanks for the read. I'll keep you guys updated as I go along.

 

[disco biscuit]

Good show. Keep us updated for sure...

 

[Bosnian Discovery]

It looks like the majority of the leak can be attributed to the camshaft position sensor because it was replaced at some point and reinstalled without an O-ring. The oil managed to find it's way to the crank pulley which would sling it all over the cover and engine bay. Also the bolts that hold the timing cover to the block and the water pump to the cover were only slightly more than finger tight, leading to a seeping gasket all around. Go figure.

On top of that the little metal clip that holds the plug to the oil pressure sensor is missing, meaning that the plug was loose, potentially getting intermittent signal.

And even on top of THAT, the idler pulley orientation was reversed, with the larger (80mm) pulley installed on the passengers side of the engine near the tensioner and the smaller (70mm) pulley installed on the drivers side near the AC compressor.

Needless to say I have very little faith in whatever mechanic the previous owner used.

Currently waiting on parts to come in so I can wire and install a water temp and oil pressure gauge. Once that's done I'll begin to reassemble.

 

[columbiar]

Thanks for the write up. I am actually getting stuff ordered to do much of the same thing. Something I didn't consider were the pully bearings. Is this something I should just plan on doing while I'm in there due to mileage (120K)? Or is there a way to know that they need replaced?

Also, where did you order the new bearings?

Thanks

 

[MR.T]

Yeah, stoked on this. Been needing to do it for some time now. Bookmarked.


Sent from AutoGuide.com App

 

[Bosnian Discovery]

@Columbiar - Replacing the pulleys is good general preventative maintenance, but if they're in good shape there's nothing wrong with leaving them in. All three parts (tensioner, small pulley, large pulley) are easily accessible even without the front torn down so it's not terribly hard to get back in there to replace them. A good idea is to pull your belt off and spin all three pulleys by hand - if you hear any scraping or grinding or notice any flat spots, it's time for them to be replaced. Both of my idler pulleys fell into this category and my tensioner spring was weak so I replaced everything. My pulleys were solid steel so the replacement was easy, but if yours are plastic I'd just replace the whole thing.

I got the parts from Amazon - bearing #6203 for the 70mm pulley and #6304 for the 80mm pulley. Just shy of $24 for both. It's also not a bad idea to get some assembly lube to make reassembly easier. I have Amazon Prime so shipping was free - but if you don't factor in another $10-$12 for shipping. Aftermarket pulley replacements run $25 for the small one and $45 for the big one, so you're definitely saving money. I also went with a Gates tensioner as I've had good experience with the Gates brand and they guarantee the part for the entire belt-change interval, which is 100,000 miles.

6203-2NSE Nachi Bearing 17x40x12 Sealed C3 Japan Ball Bearings: Amazon.com: Industrial & Scientific

6304-2NSE Nachi Bearing 20x52x15 Sealed C3 Japan Ball Bearings: Amazon.com: Industrial & Scientific

I would HIGHLY recommend getting these same Nachi bearings, but whatever you use make sure they have the rubber (not metal) seal on both sides. Japanese and Italian bearings are the best - don't bother with the Chinese or UK bearings as they're notorious for being out-of-spec and failing early. My OEM pulleys had one Japanese bearing and one UK bearing and the UK bearing was far worse off.

There are several how-to's on Youtube that describe pulley bearing replacement, so just cobble together what works best for you. I simply pounded out the old bearings with a hardwood dowel and a dead blow hammer, cleaned the seating surface on the pulley with some #0000 steel wool and WD-40, and used my bench vise and a similarly-sized socket to press them back in. The most important thing to remember when you're pressing them in is to exert the same force on both the inner and outer race rings at the same time - if you try to hit the rubber seal you'll deform the bearing and have to start from scratch.

Thanks for the comments guys - feel free to ask any questions you may have regarding the process on your own trucks as I've done my research and feel quite confident with this job. Below are some of my tips.

The two parts of the job that trip most people up (removing the fan and the crank pulley) ended up being quite easy. I hit both parts with some PB Blaster the night before I started working and I feel it really helped. Advance Auto "rents" the fan clutch tool for $69.99 (but you get the full amount back when you return it) and it really helps, but a large adjustable wrench or a homemade part will also do. With the belt still in place, simply slide the 36mm wrench on the clutch nut and tap it a couple of times with a hammer. It comes loose with minimal effort (check out Youtube for this as well) and the fan just spins off, just be careful not to drop it as your risk breaking a blade. With the belt still on it's also a good idea to loosen the water pump and power steering pump pulley bolts - they're not held on with a lot of torque but its definitely easier than trying to loosen them without the tension of the belt.

Do the crank pulley last, after you pull the oil pan. Many guys slip a 15/16 socket on the bolt, wedge a breaker bar against the frame or ground, and then bump the starter to loosen the bolt - it works great, but it's a little more involved than what I did. I simply wedged a soft pine 2x4 between the crank and the block to prevent the engine rotating, and loosened the bolt with a 36" breaker bar. ONLY USE WOOD OR PLASTIC AS A WEDGE - a metal pry bar can damage the engine surfaces. Once again, the bolt came off effortlessly.

P.S. Both bolts are standard thread (lefty loosey, righty tighty).

Other than those two "problem areas", literally everything else is a simple matter of unbolting parts and keeping things organized. Everything comes off easy and the access is pretty great. I cut my mechanic teeth on sport compacts, so an engine bay this spacious is a godsend.

Another pro tip is to purchase a good assortment of quality o-rings to have handy before you start. They run less than $15 on Amazon (Neiko Tools Pro-Grade 419-Piece Universal O-Ring Assortment Set - Metric - Amazon.com) and will save you so much time and money in the long run. There are o-rings on the oil strainer, oil filter adapter, cam position sensor, and even the pulleys (they hold the bolts in). It's a good habit to replace them as they are all dried due to the heat of the engine and could lead to internal and external leaks.

Yet another pro tip is to pull the 2 large oil cooler plugs and 1 smaller oil pressure test plug from the timing cover, replace the cooler plug o-rings and then wrap all three with thread tape and torque them back down. All three of these plugs tend to back off with age and are a big cause for leaks.

As for my own project? Well it got cold here in FL last night (61F - it's absolutely freezing) so I took a break, but tonight I plan on throwing the stripped timing cover and some other components into the parts washer to get them extra-clean before I hit them with a coat of self-etch primer and engine enamel. I try to get into the habit of cleaning and painting components that I pull so that it's easier to find leaks later on.

Then tomorrow night I'm wiring and installing my new oil pressure and water temp gauges. I went with Glowshift's "MaxTow" series as they match my factory gauges and feature both an analog and digital readout. Most analog oil pressure gauges don't read accurately down to 10-15 PSI so they wouldn't be of much use. This will help me keep an eye on things. My plan is to integrate a dual gauge pod onto the steering column shroud to keep everything looking as factory as possible. I'll take pictures of this as well.

Amazon.com: MaxTow Water Temperature Gauge: Automotive

MaxTow Oil Pressure Gauge : Amazon.com : Automotive

Sorry for the long post, but I'll keep be coming back with pictures and more info soon!

 

[ArmyRover]

Honestly it seems like the 03/04s had a problem with destroying the oil pump gears. Probably because of the misalignment of the timing cover and the block. I've seen a few that have gone a long time in that condition

 

[acg]

Bosnian,

I compliment you on posting the photos and write-up! This is very useful info and definitely a sticky for me.

Thanks for the info and pics. :clap:

 

[acamato]

Great write up, there are a couple of items I disagree with.

When installing the bearing in the pulley, you want to apply the force/load to the outer race not the inner and outer race. Match the outer race diameter up to a socket to press it in.

And you say analog oil pressure gauges are inaccurate below 15 psi. Most oil gauges use electrc sender which sends a signal to the digital or analog gauge. If an analog gauge us getting the same signal as a digital gauge how can the analog be inaccurate compared to the digital gauge? I think you meant mechanical oil pressure gauges.

 

[columbiar]

Thanks Bosnian! This is pure gold for me. Keep us updated on the project. I will be using this write up soon.

 

[Bosnian Discovery]

@acamato - I agree about the bearings. Focus on the outer ring but make sure that you keep the force even to prevent the pulley from distorting. The metal bushing that pulley bolt lines up through is perfect to use as a base plate in your press or vice as it will distribute force evenly

As for the analog gauges, I misspoke when I said inaccurate - what I meant was that most analog gauge readouts don't focus on detail in the numbers below 20-25 PSI. So basically the gauge has a small gap from 0-25 PSI before the gaps become bigger from 25-100 PSI. So at a glance, it would be difficult to discern if you're getting 10 PSI or 15 PSI - and that could be the difference between engine failure. See below:





It's just easier to get quick readings from a digital gauge. You don't have to take your eyes off the road and you know exactly where your oil pressure is.

Back to the project - only managed to do a bit more last night. I cleaned off the timing cover and oil filter adapter with mineral spirits and taped off the sealing surfaces so that I could hit it with a coat of primer and paint. The paint is the same silver I used for my calipers so I know it will hold up well. The silver matches the color of the brushed aluminum well so it will look stock, but finding leaks and cleaning will be made much easier later on. So far I only primed it (no photo yet), but I'll do the top coat tonight and post pictures after it's cured this weekend.





And yesterday I put an order into Jegs for the electric fan conversion. I picked up an aluminum shroud, 2200 CFM fan, and the dry-probe control kit. I feel that 2200 CFM should be adequate, but the shroud's mounting pattern allows me to upgrade to a higher flow fan if I need to. The fan does draw nearly 19 amps, but switching to the Bosch alternator I'm installing should get me 10 more amps than the Valeo, meaning the system should be up for it. I'm going to set the thermo switch to 185F which should keep me cooler than the OEM fan.

The parts:

Jegs 52110 16" S-blade fan. Draws 18.9 amps, flows 2200 CFM.



Jegs 52065 Aluminum Shroud. Matches the core size of the OEM radiator almost exactly and is pre-drilled for the 52110 fan. I'll have to get creative with mounting ideas, but I think I've figured something out:



Jegs 52125 Adjustable temp switch. Adjustable from 160F-240F which is the perfect range for our trucks. I'll wire it (fused of course) to a constant +12V source so that it can keep running for a few minutes after the engine is off to prevent heat soak. I'm also planning on wiring a manual override switch in case the adjustable one fails or in case I feel I need additional cooling.



I'm pulling the radiator tonight to give it a light external cleaning and then I'll be mounting the shroud and fan this weekend. I'll post photos and a basic writeup, of course.

 

[Dane!]

I'm interested in your cooling design, I can't wait to see results.

 

[columbiar]

Something occurred to me about the water pump. Since I just replaced the water pump a couple months ago, the seal should be fine. So, would it be possible to remove the front cover by just taking out the three long bolts and leave the others in place? Then I could replace the long bolts with some hylomar when I put the front cover back on and be good to go. Is there a reason this would not work? Thanks.

 

[columbiar]

Here is the order I plan on starting my tear down, hopefully tomorrow. If I should be doing this in a different order, please let me knowl

1. Drain coolant
2. Drain oil
3. Remove oil pick up strainer from front cover.
4. Disconnect oil cooler pipes
5. Remove oil pan
6. Remove from cover
7. Remove timing gears and chain
8. Refit going backwards

I'm assuming the oil pan has to come off to get the front cover off. Thanks!

 

[Dane!]

I had to remove my radiator, to get my impact wrench in there to pull the crank pulley, it provided extra arm space also. You do have to drop the pan to get the timing cover off, I had a good 2 inches of carbonized oil in the bottom of my pan... so I cleaned it to look almost new, seems the previous owners didn't change the oil too often I'm assuming. As for you water pump question I'd have to look. I actually have the fan and serp belt off to service my idler pulleys, I have a squeak in the morning (when cold) and a Hum when warm, no other accessory is squeaking when I hand turn them so Im hoping its the bearings, this thread actually made me commit to doing it. (Thanks) lol. :clap:

 

[Bosnian Discovery]

@Columbiar - You can leave the water pump attached - it's common practice unless you're replacing the seal. Keep in mind that removing the water pump and power steering pulleys will help with access and it's pretty easy.

As for your checklist, you can't remove the oil strainer until you remove the oil pan - just be sure to look in the RAVE for the pan bolt locations as some are pretty hidden - if the pan won't come loose you've likely left a bolt installed - it's heavy enough that it'll drop under it's own weight when you've gotten all the bolts, don't try to force it.

Back to my project. I got the timing cover rebuilt, the e-fan conversion done, and I got the steering box back in. Hopefully the seals I changed will stop the leaking. I was planning on getting the car running yesterday, but I noticed my PCV valve was totally clogged and my valve cover gaskets were seeping oil so I pulled the upper IM and valve covers to clean everything up and reseal it. By the time I did all that it was too dark to continue working. Below are some photos.

1. The fan/shroud setup. The JEGS shroud fit almost perfectly. The top flange was a bit too long so I folded it over around the top of the radiator so that it can carry the weight of the setup without stressing the fins. The bottom of the flange slips perfectly into the OEM shroud clips at the bottom of the radiator so the weight of the whole thing is carried by the radiator frame rather than just the fins and cooling channels. I used some quality radiator-fan mounts (the zip-tie kind) to ensure a good seal between the radiator and the shroud and to make sure the thing doesn't jump around. The temp probe is installed at the radiator inlet to ensure accurate readings. I think it came out quite nice.

It remains to be seen if the 2200CFM fan will be enough to cool the car in Florida summers, but it shouldn't be too tough to replace it with a higher-flowing fan if it doesn't. There's quite a bit of room between the fan and the timing cover so future maintenance should be easier, and the OEM shroud (the one that holds the cooling hoses) still fits, so it will be a clean install.






2. The timing cover. I got it cleaned and painted. Two coats of engine primer, two coats of caliper paint, and two coats of engine clear, followed by a 200F bake to cure it. The part is nice and shiny and will make finding leaks quite easy. I installed a new crank seal, and refit the oil filter adapter with a new o-ring and some RTV to make sure that no leaks pop up in the future. I also added thread tape to all 3 plugs to ensure no future leaks. I will be installing the new sender for the oil gauge this weekend. The new oil pump gears went in with no problem - they spin freely and fit perfectly. I packed the gears with assembly lube and petroleum jelly to ensure a good prime when it comes time to start the motor. The cam position sensor was refit with a new o-ring and a bit of RTV to ensure a positive seal.




Hopefully next weekend I'll be able to reassemble everything and wire the gauges and fan. The hardest parts are done. Which is good, because I really miss my car.

 

[columbiar]

Wow! That looks better than brand new. Very nice.