Compression test results.
Lead Driver
Joined: May 2007
Posts: 5,613
Likes: 9
From: Flagstaff, Arizona
damn Kris.....never realized how much you have put into that truck, I'd be bummed out too. If it IS low compression.....then what? I'm no mechanic by any means, but it sounds like a major project 
Post Fiend
Joined: Sep 2006
Posts: 5,584
Likes: 0
From: Millbrook Alabama
Well everyone else has pretty much said it, but I will too. UMMM, Ouch.
thats the drop in .84 TN right? Not that I am ragging on TN, just couldnt remember if it was the .84 or the 1.0. When was your last oil anaylisis? ( I dont want to start a UOA fight with anyone either..... Mike, sit down
) Any indications of long term wear? Have you pulled the turbo apart yet to see if any bearing damage is evident?
Two words: Motor Honey!
discalimer: to anyone else who doesnt get the motor honey joke, dont put that ***** in your engine, or you will cuse real damage.
thats the drop in .84 TN right? Not that I am ragging on TN, just couldnt remember if it was the .84 or the 1.0. When was your last oil anaylisis? ( I dont want to start a UOA fight with anyone either..... Mike, sit down
) Any indications of long term wear? Have you pulled the turbo apart yet to see if any bearing damage is evident?Two words: Motor Honey!
discalimer: to anyone else who doesnt get the motor honey joke, dont put that ***** in your engine, or you will cuse real damage.
Senior User
Joined: Jun 2003
Posts: 369
Likes: 0
From: Colorado Mountain Country
Well...
My curiousity has been peaked, not in a positive way unfortunatly. Since Kris has a '02, and I have an early '03, this is concerning. I share many of the upgrades (minus the tranny & HPOP) he has done, and am looking for the next step. Minus my 1 1/2 year old oil leak, no new issues. I haven't had the chance to dyno yet, and I missed my DP Live Session because my truck got broken into and thrashed the week before.
Kris, is that a TN Bushing turbo or did you get Kevin to upgrade it to the BB unit?
Just curious because my original TN unit exploded big time after just 6 months of service. I put it in my truck in late June '07 and first week of Jan '08, BOOM. TN said the failure rate was pretty high. Just a thought...... I'm very interested in you're data and experience because I feel like our rigs are fairly similar in terms of "experience"..... I want to help out because much of what you've contributed has helped me, and I hope to re-pay that at some point.
Gotta put it out there, this turbo is really suspect to me... REALLY....
Any new info?
-Kevin
My curiousity has been peaked, not in a positive way unfortunatly. Since Kris has a '02, and I have an early '03, this is concerning. I share many of the upgrades (minus the tranny & HPOP) he has done, and am looking for the next step. Minus my 1 1/2 year old oil leak, no new issues. I haven't had the chance to dyno yet, and I missed my DP Live Session because my truck got broken into and thrashed the week before.
Kris, is that a TN Bushing turbo or did you get Kevin to upgrade it to the BB unit?
Just curious because my original TN unit exploded big time after just 6 months of service. I put it in my truck in late June '07 and first week of Jan '08, BOOM. TN said the failure rate was pretty high. Just a thought...... I'm very interested in you're data and experience because I feel like our rigs are fairly similar in terms of "experience"..... I want to help out because much of what you've contributed has helped me, and I hope to re-pay that at some point.
Gotta put it out there, this turbo is really suspect to me... REALLY....
Any new info?
-Kevin
Senior User
Joined: Jun 2003
Posts: 369
Likes: 0
From: Colorado Mountain Country
Gotta add this, my bushing TN unit was leaking oil into the exhaust side, and was WAY down on boost. Not trying to flame Turbonetics because they did replace my blown unit, well, I did pay the BB upgrade fee, and, after a 3 month wait, I got a new BB 1.0 unit. I was told they were working these new units through R&D and quality control to ensure that the product was OK. So far, all's well. Making 23ish PSI with the red wastegate line hooked up...
Thread Starter
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Post Fiend
Joined: Jul 2005
Posts: 14,582
Likes: 12
From: 21791
I have the .84 housing, want to upgrade to a 1.0 housing though. It's the bushed version, i dont want to spend the $$ for the BB one, as i dont think im going to have it much longer. I havent taken it apart to look for any internal damage, but if i do the 1.0 housing, i WILL tear at least the compressor and exhaust housings off and look at it. BTW i do not have the HPOS anymore, it too leaked and i returned it, now i have a new-reman stock pump with BO tuning still, and that might be part of the reason why i cant hold but 1800psi.
I lost over 4 gallons of oil when i had problems with my terminator.... So basically i changed the oil then, but it just took a few weeks. I don't remember the last time i changed the oil (mileage) but the latest Blackstone report in my email says 8/31/07, but that's not many miles for me. Maybe 7500 at the most with 4 added gallons in between. Maybe i should send a sample in.
I lost over 4 gallons of oil when i had problems with my terminator.... So basically i changed the oil then, but it just took a few weeks. I don't remember the last time i changed the oil (mileage) but the latest Blackstone report in my email says 8/31/07, but that's not many miles for me. Maybe 7500 at the most with 4 added gallons in between. Maybe i should send a sample in.
Fleet Owner
Joined: Jun 2004
Posts: 25,090
Likes: 1,112
From: Rio Rico, AZ.
Did a compression check today, brought on by the advice of several people who are helping me trace my low power problems. The truck just feels weaker and weaker as time goes on, plus i get significant blue smoke on startup for a few seconds, and every consecutive time i dyno the number gets lower and lower. These readings are of the engine bone cold, each set 15 seconds or so to stabilize pressure.
Cylinder 1- 390psi
Cylinder 2- 380psi
Cylinder 3- 380psi
Cylinder 4- 380psi
Cylinder 5- 365psi
Cylinder 6- 400psi
Cylinder 7- 400psi
Cylinder 8- 385psi
What do you think?
Cylinder 1- 390psi
Cylinder 2- 380psi
Cylinder 3- 380psi
Cylinder 4- 380psi
Cylinder 5- 365psi
Cylinder 6- 400psi
Cylinder 7- 400psi
Cylinder 8- 385psi
What do you think?
100% agree on this one. It will fire with extreme difficulty when the engine is cold, but once it warms up, it is not noticable.
Again, the low compression threshhold is simply the need to heat the air hot enough to fire the fuel.
Sled pullers drop thier compression down so low that it requires starter fluid just to get the engine running and they make massive HP.
This seems really low to me and along with a flaky turbo, that is what I would pursue to get the power restored.
.
Again, I agree that your compression numbers are low, but right now is NOT the cause of your power loss.
Your compression readings will only give the symptom of hard starting in the winter, and some excessive blow by from the oil filler cap. Nothing more.
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Post Fiend
Joined: Jul 2005
Posts: 14,582
Likes: 12
From: 21791
Thanks dan, that's what im leaning on right now. I dont think anything really is wrong with the turbo, as i can still make 34psi out of it on stock injectors, but i need to resolve the low ICP problem.??
Fleet Owner
Joined: Jun 2004
Posts: 25,090
Likes: 1,112
From: Rio Rico, AZ.
Sort of like the reverse of a 10k mod that increases HPOP pressure for a good increase in power.
If this were my truck I would get that resolved before looking anywhere else.
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Postmaster
Joined: Jun 2006
Posts: 2,647
Likes: 0
From: Fulltime RVer
As I explained below, the ideal theoretical maximum cranking pressure for a PSD is 769.8 psi, but due to incomplete filling of cylinders, some blow by, etc.., actual values for a new engine are in the mid 400's.
Analysis of compression test results!
https://www.ford-trucks.com/forums/6...t-results.html
The auto-ignition temperature for #2 diesel is 558 K, and if there's no external heating from the glow plugs or AIH, a minimum cranking pressure of 455.7 psi is necessary for self starting at an ambient temp of 80 F. So at lower ambient temps, even a new engine requires an external heat source for starting!
However, I agree with Dan that modestly low cranking pressure doesn't cause a power loss, as long as the fuel and air supply are adequate. I used to remove one of the compression rings on my race car engines to make it go faster. At higher RPM the effective cylinder pressure that produces HP is caused by the combustion of fuel (not the compression of air), and the reduced friction from fewer rings actually increases flywheel HP, even though it reduces cranking pressure.
Analysis of compression test results!
https://www.ford-trucks.com/forums/6...t-results.html
The auto-ignition temperature for #2 diesel is 558 K, and if there's no external heating from the glow plugs or AIH, a minimum cranking pressure of 455.7 psi is necessary for self starting at an ambient temp of 80 F. So at lower ambient temps, even a new engine requires an external heat source for starting!
However, I agree with Dan that modestly low cranking pressure doesn't cause a power loss, as long as the fuel and air supply are adequate. I used to remove one of the compression rings on my race car engines to make it go faster. At higher RPM the effective cylinder pressure that produces HP is caused by the combustion of fuel (not the compression of air), and the reduced friction from fewer rings actually increases flywheel HP, even though it reduces cranking pressure.
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Post Fiend
Joined: Jul 2005
Posts: 14,582
Likes: 12
From: 21791
Thanks for all the info Dan and Eugene. I don't know if this is a possiblity, but could the two fittings in the oil rail under the valve cover be leaking oil? That's the only way i can see a brand new pump losing this much pressure. Even used, 70K+ pumps are getting 2900psi on stock injectors, and now me with a fresh new one (i can only assume it's a 17*, i know joey wouldnt do that to me) i can hold around 2000 on 60t, which actually feels much stronger on the top end. Could stressed injector o-rings (having to deal with 3850+ psi) cause some oil to leak by?
Lead Driver
Joined: Oct 2004
Posts: 7,413
Likes: 1
From: Columbia, MO
Kris, your BO tunes are probably hurting power, at least a little bit. IIRC, the timing for BO is retarded a little, which would hurt power on standard oil.
I don't know that injector o-rings would let oil leak by. As tight as they fit into the injector cups, I would think it's an all or nothing type of deal. Just tossing some ideas here, but an IPR that wasn't working propery might cause a problem, especially if it's sticking partially open.
Kris, call me tomorrow when you get some time. I'll give you the rundown.
I don't know that injector o-rings would let oil leak by. As tight as they fit into the injector cups, I would think it's an all or nothing type of deal. Just tossing some ideas here, but an IPR that wasn't working propery might cause a problem, especially if it's sticking partially open.
Kris, call me tomorrow when you get some time. I'll give you the rundown.
Senior User
Joined: Jun 2003
Posts: 369
Likes: 0
From: Colorado Mountain Country
Hey Kris, just a side question. How on earth are you making 34psi? I'm certainly not questioning this, more so just curious so I can get to the 30ish psi mark...
Thanks for the info....