Compression Test on e450?
#1
04-19-2018, 12:35 PM
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Compression Test on e450?
Greetings all!
I'm new here and hoping that someone has experience checking compression in an e450. I've looked all over the internet but can only find information on doing so in the f-series.
As some of you may know, there is very little room to work inside and I'm concerned that the limited space may present even more difficulties than normal when checking compression on the 7.3. My current plan is to customize the cheap harbor freight kit until it works, that way I'm not out much if it doesn't.
Any recommendations are greatly appreciated!
I'm new here and hoping that someone has experience checking compression in an e450. I've looked all over the internet but can only find information on doing so in the f-series.
As some of you may know, there is very little room to work inside and I'm concerned that the limited space may present even more difficulties than normal when checking compression on the 7.3. My current plan is to customize the cheap harbor freight kit until it works, that way I'm not out much if it doesn't.
Any recommendations are greatly appreciated!
#2
04-19-2018, 04:06 PM
Do the quick blow by test first. With the engine idling, remove the oil fill cap and place it on the hole upside down.
If it just sits there, then good. If gasses blow it right off, then a compression test is warranted.
I'm lazy, so if blow by is fine, I would not do a compression test. Why do you want to do the test? Symptoms? Or just peace of mind?
And also, Welcome to FTE!
If it just sits there, then good. If gasses blow it right off, then a compression test is warranted.
I'm lazy, so if blow by is fine, I would not do a compression test. Why do you want to do the test? Symptoms? Or just peace of mind?
And also, Welcome to FTE!
#3
04-19-2018, 05:03 PM
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Does the blowby test work with the extension tube? If that question doesn't make sense, I'm referring to the fact that the oil 'cap' isn't like it is on the trucks. There's a tube that comes off the top of the engine and out to the front of the compartment and then capped there.
I want to test because its showing symptoms of needing new injectors. It's already at 214000 on stock ones, so that makes sense. The problem is that the air cleaning assembly had holes in the back and the resonator box (a plastic box that connects to the tube connecting the air cleaner and the turbo on vans) was shattered when I bought it. No way for me to know how long it was like that and how much dirty air got sucked in, and I don't want to put the money into injectors if the compression is going to be a problem.
Thanks for the response!
I want to test because its showing symptoms of needing new injectors. It's already at 214000 on stock ones, so that makes sense. The problem is that the air cleaning assembly had holes in the back and the resonator box (a plastic box that connects to the tube connecting the air cleaner and the turbo on vans) was shattered when I bought it. No way for me to know how long it was like that and how much dirty air got sucked in, and I don't want to put the money into injectors if the compression is going to be a problem.
Thanks for the response!
#4
04-19-2018, 06:27 PM
I'm not familiar with the differences with the extension tube, but think it would still work. I'll defer to a van expert on that question.
But yes, if your engine has sucked dust for an unknown period of time, and you are looking at dumping some significant money into the engine, then I can see going to the trouble of a compression test first.
Another thing to look at is if your turbo wheel has been "dusted." This basically means inspecting the turbo wheel to see if the edges are rounded off. If so, this may also have affected the valves and piston rings. This would show as low compression, And I would expect a good amount of blow by too.
I also suggest getting some diagnostics from the engine before doing even the compression test. Have you heard of TorquePro or Forscan? There are members here on FTE who will gladly analyze the output from these tools. They can provide a lot of information without you having to turn a wrench.
These engines are capable of going 400,000 miles, so in theory you could still run a good long time. But I would not want to dump several thousand into repairs (injectors plus whatever else you come across) and still be looking at a complete rebuild shortly (even a couple years) after.
But yes, if your engine has sucked dust for an unknown period of time, and you are looking at dumping some significant money into the engine, then I can see going to the trouble of a compression test first.
Another thing to look at is if your turbo wheel has been "dusted." This basically means inspecting the turbo wheel to see if the edges are rounded off. If so, this may also have affected the valves and piston rings. This would show as low compression, And I would expect a good amount of blow by too.
I also suggest getting some diagnostics from the engine before doing even the compression test. Have you heard of TorquePro or Forscan? There are members here on FTE who will gladly analyze the output from these tools. They can provide a lot of information without you having to turn a wrench.
These engines are capable of going 400,000 miles, so in theory you could still run a good long time. But I would not want to dump several thousand into repairs (injectors plus whatever else you come across) and still be looking at a complete rebuild shortly (even a couple years) after.
#5
04-19-2018, 07:24 PM
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Yea, I stupidly am very far into this already. It’s a bus my wife and I converted into an rv for the fun of it. I’ve been using it as an opportunity to learn about diesels along the way and have already fixed most of the problems.
The rv rv part is nearly done, so I’m really hoping the compression isn’t too bad. I’ve watched videos on engine swaps, it seems like a real chore to get them out of these.
Can basic scans like that give data that would indicate the existence of a compression problem? If so, do you know what I would be looking for specifically?
The rv rv part is nearly done, so I’m really hoping the compression isn’t too bad. I’ve watched videos on engine swaps, it seems like a real chore to get them out of these.
Can basic scans like that give data that would indicate the existence of a compression problem? If so, do you know what I would be looking for specifically?
#7
04-20-2018, 07:28 AM
Got any pics of your project? We like pics.
I'm surprised others have not jumped in here, I think you could use some information on what is involved in pulling the valve covers in your rig. Probably a few tricks some know that would make it easier for you. I'm sure it is a bit trickier than pulling them on a truck. So this post is a bump for you.
With good batteries, wiring, and starter, and spinning for 5 puffs with all glow plugs removed, excellent compression would be 400 pounds. But many folks don't get that much pressure and the engines are still good. That is why the blow by test is important, it helps in later interpretation.
Rather than the absolute compression numbers, I look at the variation between cylinders. I'm used to using 10% variation as my standard for gas engines, but have read that the 7.3 standard is 25% variation. Yes, wow! So if all are in the range of 300 to 400, that is still in spec. Same for all cylinders ranging from 260 to 350. If you do see 400 minimum in all cylinders with only 5% variation, then be very very happy. But lower numbers combined with minimal blow by can also be OK.
ETA: Post you numbers when you get them.
I'm surprised others have not jumped in here, I think you could use some information on what is involved in pulling the valve covers in your rig. Probably a few tricks some know that would make it easier for you. I'm sure it is a bit trickier than pulling them on a truck. So this post is a bump for you.
With good batteries, wiring, and starter, and spinning for 5 puffs with all glow plugs removed, excellent compression would be 400 pounds. But many folks don't get that much pressure and the engines are still good. That is why the blow by test is important, it helps in later interpretation.
Rather than the absolute compression numbers, I look at the variation between cylinders. I'm used to using 10% variation as my standard for gas engines, but have read that the 7.3 standard is 25% variation. Yes, wow! So if all are in the range of 300 to 400, that is still in spec. Same for all cylinders ranging from 260 to 350. If you do see 400 minimum in all cylinders with only 5% variation, then be very very happy. But lower numbers combined with minimal blow by can also be OK.
ETA: Post you numbers when you get them.
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#8
04-20-2018, 08:24 AM
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I'm working right now so can't post pics, but I will later.
Thanks for the info. I'll go ahead and do the blow by test, but I'm going to wait to start pulling stuff until I find someone who can shed some light on what I'm in for. I took the doghouse cover off (you can really only do this from the back, at least from what I can tell) and there are a couple specific spots that look like clearance could be a real issue.
I can run a basic scan tool like was mentioned today as well.
Thanks for the info. I'll go ahead and do the blow by test, but I'm going to wait to start pulling stuff until I find someone who can shed some light on what I'm in for. I took the doghouse cover off (you can really only do this from the back, at least from what I can tell) and there are a couple specific spots that look like clearance could be a real issue.
I can run a basic scan tool like was mentioned today as well.
#9
04-20-2018, 08:28 AM
Hotshot
I disassembled (scrapped out) an E-450 and it seems to me that you're going to have to take a lot of stuff out of the front end of your truck to perform a compression test and/or work on injectors and other things. Up pipes, on the other hand, are a piece of cake on that. If you find that you need any parts for it send me a PM, I have a good bit of stuff still hanging around.
#10
04-21-2018, 08:59 AM
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Okay, I performed the blow by test - kind of. The extension tube for the oil is at an angle, so you can't actually sit a cap on top. I placed my hand over the opening tightly and couldn't feel anything at all? I could see a tiny amount of what I assume to be the results of blow by wafting out of the hole when I first started it, but barely noticeable.
#12
04-21-2018, 11:15 AM
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I’m starting to think this beast have some life in her yet then.
I’ve talked to one person at a diesel garage who gave me some pointers on replacing the injectors from the back without too much disassembly. There’s one in particular that *may* need to have the solenoid removed to get out and in. Haven’t looked up how to do that yet, I’m hoping it’s not too difficult. Overall sounds like a doable, albeit pain in the *** job.
I’m thinking I may just proceed with the injectors without doing the actual compression test given the difficulties. I’m so far into this that I would probably put a new motor in if need be anyway, and the newer injectors would still be useful in that situation.
I’ll keep this thread updated with details and pictures of what I do for any e-series owners who come after me needing to do the same work.
walleye, I’ll let you know if I need anything after I start digging around.
a couple of questions:
What else should I definitely replace while doing injectors?
Can anyone point me to a thread on checking turbos for the e-series? I believe they are slightly different, and I’d be interested in deleting the Ebpv or at least making sure the thing is locked open. Mine isn’t connected anymore and it sometimes moves back to being shut.
I’ve talked to one person at a diesel garage who gave me some pointers on replacing the injectors from the back without too much disassembly. There’s one in particular that *may* need to have the solenoid removed to get out and in. Haven’t looked up how to do that yet, I’m hoping it’s not too difficult. Overall sounds like a doable, albeit pain in the *** job.
I’m thinking I may just proceed with the injectors without doing the actual compression test given the difficulties. I’m so far into this that I would probably put a new motor in if need be anyway, and the newer injectors would still be useful in that situation.
I’ll keep this thread updated with details and pictures of what I do for any e-series owners who come after me needing to do the same work.
walleye, I’ll let you know if I need anything after I start digging around.
a couple of questions:
What else should I definitely replace while doing injectors?
Can anyone point me to a thread on checking turbos for the e-series? I believe they are slightly different, and I’d be interested in deleting the Ebpv or at least making sure the thing is locked open. Mine isn’t connected anymore and it sometimes moves back to being shut.
#14
04-21-2018, 12:06 PM
