1988 E350 7.3 Hypermax

[Ballalu]

Hello everyone,

I’m new to this forum, but have been browsing for the past couple of days. I am new to diesels, but have some basic automotive experience. My father will be assisting me with various parts of my adventure; he’s been an auto mechanic for 45 years, but doesn’t know much about diesels.

I just picked up a 1988 E350 Hightop with a 7.3 hypermax turbo. It’s reported to have roughly 120,000 miles on it, however it rolls over at 99,999 and the odometer stopped working at 303 miles.

I flew out to Spokane and then drove back to Sacramento CA. I babied the van; the EGT would jump quickly with any kind of grade/climb. Even on flats it would be around 600-800 going 60-65; when on grades I would have to go 40-55 to maintain less than 1k temperatures. I figured something was wrong and opted to go slow than straight murdering the motor.

When I arrived home 24 hours later; I finally got the doghouse cover off and found what I imagine are issues. I have scoured several of the postings here and have gathered some basic thoughts with possible corrections.

1) photo 1 The former CDR valve hole on the intake manifold is wide open/unplugged. Would this cause excessive heat and cause the motor to be underpowered? It is essentially a major leak in the intake system. I contacted hypermax and they are going to send the appropriate plug to me (I was surprised, but glad to be working with their product).

2) photo 2 Oil, oil everywhere. The hypermax kit has the CDR moved towards the driver side with the kits requiring the crankcase to be vented from the valve cover to the CDR. My Valve cover was instill vented by a coolant? Hose to underneath the transmission. My plan is to reconnect that to the CDR valve. The plastic elbow was also not sitting well in the valve cover.

However, there is also a ton of oil sitting in the valley pan. It’s right next to the turbo oil return line. I’m hoping it just a busted seal; I’ll get around to cleaning it and seeing what I can see. Can I buy that seal new if that’s all it is?

3) photo 3 I believe I have a C6 transmission; the “D” is not circled showing that there is not an overdrive. I also only heard the 2 shifts. However, when I got underneath the vehicle, I found it to have DNE2 overdrive transmission attached. I can’t find much about it other than it’s no longer serviced and is essentially replaced by GV. The interior of my van does not have the overdrive/underdrive controller anywhere inside. However, I also read that it’s a potentially simple electric switch to make it function; any solutions or guides for that? Is it worth the headache?

4) photo 4 While looking at the transmission, I found several plugs/wires disconnected nearby. I’m wondering if these are my VSS/equivalent sensors. One looks like my previous VSS on a Subaru. Getting these to their correct home I am hoping would potentially solve my odometer, speedometer and cruise control issues.

5) It has a “Devils Own” water/methanol system installed. Previous owner has never had it working and I don’t intend to use it either. Can I simply cut the water intake line and cap it?

6) Underneath the turbo there is also this little wire/vacuum hose connector. What is this?

I should’ve done more research/investigation before I made the purchase. But here I am. Going to be using sweat equity to make this into my future family camper, as long as I can get it running well. Thanks everyone!

 

[Ballalu]

Photo 1 for Point 5
Photo 2 for point 6

 

[Cubey]

1200 is the max you want to do on egt. 1000 on grades is normal.

600-800 at highway speeds is normal too

it's a c6. there would be a separate factory button for overdrive to the left side of the steering column, plus E4OD didn't come out until 1989

The c6 itself has no wires at all, except for the neutral safety switch. the wires you have go to the dne2 probably.

Just google dne2 and you'll see forums galore talking about it.

a thread here:

US Gear Dual Range / Doug Nash Info

Since there seems to be a number of different places for info on these, I'm starting this thread to try and consolidate it all in one spot. We'll see how it works... Both the US Gear Dual Range and Doug Nash DNE2 boxes are designed as add on 2 speed auxiliary gear boxes useful for either a...

www.oilburners.net

A page that talks about hyperMax van kit with some pictures.

Hypermax Van Turbo Install for the 7.3 IDI in a 1988 Ford Clubwagon - IDI Online

After two years of searching, I was not able to find a used van turbo kit for my 7.3 IDI. I assumed that even if I found a used IDI van turbo kit, it would cost me at least $750-$1000. I waited long enough, saved up a little, and decided to buy a new Hypermax

www.nickpisca.com

 

[KansasIDI]

That plug would of course be needed to make any kind of boost.

Hypermax customer service is some of the best that I have ever experienced. Their products are spectacular as well. Get it all fixed up and I’d bet it will run real good.

 

[IDIBRONCO]

1) photo 1 The former CDR valve hole on the intake manifold is wide open/unplugged. Would this cause excessive heat and cause the motor to be underpowered? It is essentially a major leak in the intake system. I contacted hypermax and they are going to send the appropriate plug to me (I was surprised, but glad to be working with their product).

Yes this could and probably did cause both issues. With that hole open, you have a HUGE boost leak, meaning that you'll build little to no boost. This will cause a lack of power since you basically have a N/A engine right now. Assuming that the fuel has been turned up for the turbo, it will also cause higher than normal EGTs since you don't have enough air to burn all of the extra fuel.

My Valve cover was instill vented by a coolant? Hose to underneath the transmission.

Whatever was used, it's called a road draft tube (RDT). As you can see, it vents the crankcase gasses to the atmosphere. Some people like them, some don't. It does kind of look like your vehicle is on fire. Since you live in California, I think it would be best to remove this and reconnect it like you are already planning to do. I'll bet that this is a big no-no in California.

However, there is also a ton of oil sitting in the valley pan. It’s right next to the turbo oil return line. I’m hoping it just a busted seal;

Clean it up, install the new plug after you get it, and observe. The oil may be coming from that open hole in the intake. Some oil does, or did in your case, go back through the turbo and into the intake. This comes from the crankcase gasses being redirected back into the intake to be reburned. Remember that these engines have very large ring gaps by design so there is a lot of blow by compared to most other engines. A lot of blow by also doesn't mean the your engine is bad.

Is it worth the headache?

Yes it is! In my opinion, the C6 is lacking for modern fay highway speeds. It (obviously) has no overdrive and there's quite a bit of built in slippage in the torque convertor because it's not a locking convertor. If you ever have to remove the transmission, it may be worth your while to install a low slip convertor. They're not cheap, but will help to increase you fuel mileage and reduce trans fluid temps because there will be less slipping in the convertor.

Can I simply cut the water intake line and cap it?

I don't know much about water/m e t h set ups, but I'm guessing that you'll be fine to cap off the water line.

6) Underneath the turbo there is also this little wire/vacuum hose connector. What is this?

Due to the location of the wire and the shape of the connector on the end, my guess is that it's the wire for the factory oil pressure sender. In your case, I believe that you have a light instead of a gauge.

I should’ve done more research/investigation before I made the purchase. But here I am. Going to be using sweat equity to make this into my future family camper, as long as I can get it running well. Thanks everyone!

More research? Maybe, maybe not. I think with a little work, you're going to be happy with this. It should make for a pretty decent camper.

 

[rreegg]

Hey @Ballalu welcome and awesome rig you got there. I also got an '88 but it's N/A - lots of great vehicles in eastern WA/western ID area in my opinion. Sounds like an exciting trip even if there's some work to do. Nothing technical to add on this one and many others are more knowledgable but good luck with things

 

[Cant Write]

Us van owners wanna see inside photos!! What’s your standup height?

Should you not want the AUX OD, you could do as posted above, low slip converter and maybe even swap in a higher geared axle. What axle does it have now?

It drove and got you home! These things are awesome. Welcome

 

[Ballalu]

1200 is the max you want to do on egt. 1000 on grades is normal.

600-800 at highway speeds is normal too

it's a c6. there would be a separate factory button for overdrive to the left side of the steering column, plus E4OD didn't come out until 1989

The c6 itself has no wires at all, except for the neutral safety switch. the wires you have go to the dne2 probably.

Just google dne2 and you'll see forums galore talking about it.

a thread here:

US Gear Dual Range / Doug Nash Info

Since there seems to be a number of different places for info on these, I'm starting this thread to try and consolidate it all in one spot. We'll see how it works... Both the US Gear Dual Range and Doug Nash DNE2 boxes are designed as add on 2 speed auxiliary gear boxes useful for either a...

www.oilburners.net

A page that talks about hyperMax van kit with some pictures.

Hypermax Van Turbo Install for the 7.3 IDI in a 1988 Ford Clubwagon - IDI Online

After two years of searching, I was not able to find a used van turbo kit for my 7.3 IDI. I assumed that even if I found a used IDI van turbo kit, it would cost me at least $750-$1000. I waited long enough, saved up a little, and decided to buy a new Hypermax

www.nickpisca.com

Thanks for the information; it will be nice knowing what the norms should be once I get the motor running well again. I will have to investigate deeper on the DNE2, it would be cool to get it operational again, but I am not holding my breath.

Hey @Ballalu welcome and awesome rig you got there. I also got an '88 but it's N/A - lots of great vehicles in eastern WA/western ID area in my opinion. Sounds like an exciting trip even if there's some work to do. Nothing technical to add on this one and many others are more knowledgable but good luck with things

It was definitely a fun trip, even with being worried about the van overheating on every climb! I expected it to handle very poorly too, but it actually rode and drove really well I thought.

Yes this could and probably did cause both issues. With that hole open, you have a HUGE boost leak, meaning that you'll build little to no boost. This will cause a lack of power since you basically have a N/A engine right now. Assuming that the fuel has been turned up for the turbo, it will also cause higher than normal EGTs since you don't have enough air to burn all of the extra fuel.

Whatever was used, it's called a road draft tube (RDT). As you can see, it vents the crankcase gasses to the atmosphere. Some people like them, some don't. It does kind of look like your vehicle is on fire. Since you live in California, I think it would be best to remove this and reconnect it like you are already planning to do. I'll bet that this is a big no-no in California.

Clean it up, install the new plug after you get it, and observe. The oil may be coming from that open hole in the intake. Some oil does, or did in your case, go back through the turbo and into the intake. This comes from the crankcase gasses being redirected back into the intake to be reburned. Remember that these engines have very large ring gaps by design so there is a lot of blow by compared to most other engines. A lot of blow by also doesn't mean the your engine is bad.

Yes it is! In my opinion, the C6 is lacking for modern fay highway speeds. It (obviously) has no overdrive and there's quite a bit of built in slippage in the torque convertor because it's not a locking convertor. If you ever have to remove the transmission, it may be worth your while to install a low slip convertor. They're not cheap, but will help to increase you fuel mileage and reduce trans fluid temps because there will be less slipping in the convertor.

I don't know much about water/m e t h set ups, but I'm guessing that you'll be fine to cap off the water line.

Due to the location of the wire and the shape of the connector on the end, my guess is that it's the wire for the factory oil pressure sender. In your case, I believe that you have a light instead of a gauge.

More research? Maybe, maybe not. I think with a little work, you're going to be happy with this. It should make for a pretty decent camper.

This is fantastic. Really said everything I wanted to hear about the motor; plugging that hole should resolve my most worried about problems. I will definitely reconnect the blowby tube back to the CDR; even if I was not in CA, I do not want to be seeing or smelling that.

I will definitely look into the low slip convertor; are there any real downsides to the product?

Us van owners wanna see inside photos!! What’s your standup height?

Should you not want the AUX OD, you could do as posted above, low slip converter and maybe even swap in a higher geared axle. What axle does it have now?

It drove and got you home! These things are awesome. Welcome

The standup height is surprisingly 6'6" feet! I was shocked and stoked about that. I will snap some photos, but I plan to gut it once I get it running properly. I have some plans/thoughts on how I want it to be laid out. I am excited to get started on the remodel. Any recommendations on how to properly insulate it? Also, the hightop seems to leak at the windows and roof. Nothing major, but I would like to stop those before I do much else to the interior.

I have no idea what axle it has now; any idea on how to check?

 

[Cubey]

I have no idea what axle it has now; any idea on how to check?

The differential cover. It's probably a Dana 60. The ratio metal tag might still be bolted on with one of the cover bolts.

 

[IDIBRONCO]

are there any real downsides to the product?

First is the price. Summit Racing has one listed for $425 so it will cost close to $500 by the time it gets to you. The brand and part number are TCI 443630. It's called a high torque towing torque convertor. The second down side is that you have to at least slide the transmission back in order to install it. It's not an easy task but worth it in my opinion. It will help with or without the DN2. I was going to use that exact set up in my 1981 F150 until I decided to keep it with a gas engine instead of doing a IDI swap. I have one for a small block C6 that I'm going to install someday. Even though I haven't used one yet, I do believe in them.

 

[Ballalu]

So I plugged that intake manifold today and decided to take it for a spin. I rerouted the CDR with the crankcase tubing as well. EGTs still climbed high on slight grades, hitting 1100 degrees quickly while going 50 mph.

I notice that while driving and even jumping on the motor, I never have any black smoke out of my tailpipe. Some white smoke comes out when I first start it and then a small amount while idling. I am thinking that my problem is possibly in the fuel department. Either the injectors aren’t operating well or I need to adjust the IP; give the motor more diesel.

Kind of just spitballing here, curious on anyone else’s thoughts.

 

[Rocknit4x4]

Im not a mechanic by trade and most of my "knowledge" is what i have read and learned from others on this site, but it might be worth checking the timing.

 

[Ballalu]

Im not a mechanic by trade and most of my "knowledge" is what i have read and learned from others on this site, but it might be worth checking the timing.

Going to attempt to correct the timing this weekend. Unfortunately, I don’t have any of the tools for the injector pulse timing. So it’s going to be a static timing effort. The timing does fit the bill for the motor being gutless and high EGTs.

I think my CDR valve is also trashed, I can blow through it easily and there is not a diaphragm of any kind inside it.

My turbo turbine spins while the motor is running. My boost gauge I think was cracked and also connected to a no longer working water injection set up. I am going to get new gauge fittings this weekend to reassemble the boost gauge to see if I am generating appropriate boost at any point.

 

[Cant Write]

Any recommendations on how to properly insulate it?

Sorry it’s taken me so long. But here is a video I found one night that I thoroughly enjoyed and believe it to be sound.

xc_hide_links_from_guests_guests_error_hide_media

Cheers!!