EGR valve seal-- how air tight? (1 Viewer)
- Thread starter red66toy
- Start date
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I wonder if some sort of hot soapy bath in an ultrasonic cleaner would be helpful? It works great for high temperature combustion deposits on metal parts in another hobby.
As another data point (not sure how useful this is) but my old EGR valve seemed about the same as @red66toy s with regard to being able to blow a little through it. When it was installed, if you sucked hard on the hose to the VSV it would kill the engine right now. His truck would idle like crap but wouldn’t die.
We were thinking that leakage through the EGR valve could be contributing to the slightly rough idle issue, comparing our two trucks mine (with no EGR) has a noticeably smoother idle - but it shouldn’t, @red66toy has replaced/gone through almost everything with a ton of new OEM parts and he has half the miles.
I am not sure exactly how code 71 is “wired.” Does it compare EGR temp readings all the time, or just when EGR is “on?” I was somehow under the impression that it would just be checking for temp when EGR is on, but maybe it also looks at temp when EGR isn’t on, and trips when it sees elevated temperatures when EGR hasn’t been activated recently? This could explain code 71 via a small leak that is allowing the temp sensor to get hot when it shouldn’t be.
As another data point (not sure how useful this is) but my old EGR valve seemed about the same as @red66toy s with regard to being able to blow a little through it. When it was installed, if you sucked hard on the hose to the VSV it would kill the engine right now. His truck would idle like crap but wouldn’t die.
We were thinking that leakage through the EGR valve could be contributing to the slightly rough idle issue, comparing our two trucks mine (with no EGR) has a noticeably smoother idle - but it shouldn’t, @red66toy has replaced/gone through almost everything with a ton of new OEM parts and he has half the miles.
I am not sure exactly how code 71 is “wired.” Does it compare EGR temp readings all the time, or just when EGR is “on?” I was somehow under the impression that it would just be checking for temp when EGR is on, but maybe it also looks at temp when EGR isn’t on, and trips when it sees elevated temperatures when EGR hasn’t been activated recently? This could explain code 71 via a small leak that is allowing the temp sensor to get hot when it shouldn’t be.
Napa has an EGR that says it fits 88 cruisers. can't confirm or anything just found it awhile back.
Exhaust Gas Recirculation (EGR) Valve
Exhaust Gas Recirculation (EGR) Valve
4Cruisers
SILVER Star
I'll try to order one from NAPA tomorrow, I'll be running errands and will be in the neighborhood. I hope to keep my '86 FJ60 with '89 3FE running for as long as I'm able to drive. I have new or good used replacements for many of the more critical parts, just need to find a good used ECU.
It’s not ideal, but yes you can. It frees up some space too but you can’t run as much timing as you can with EGR, in order to keep the engine from pinging as you can’t change the timing curve on a 3FE like you can with a 2F.
I never thought of that. Seems like a good justification for keeping EGR.
Kleatus: Yes, any leak in egr will lead to rough engine (at low rpm). At low rpm, the egr is closed, thus leak-by makes engine run lean (too much non-fueled fumes from crankcase). At high rpms, the egr is open (leaning out as designed) and has full crankcase vent and runs well (as designed).
You can test the low rpm idle/egr scenario by whacking the egr valve with a screw driver handle. This usually allow the valve to close fully with resulting smoothing out of the engine idle.
In valve "stuck open" mode, you may be able to hear a whistle when you manually up the rpm at the carb/thorttle cable with ear to egr.
If all the above are evident, you can then "short out" the egr valve in the closed position by disconnecting the vacuum line at the top of the valve and plugging. Make sure to put a cover on the valve/vacuum line pipe so no needless debris get into the valve. NOTE: running in this condition (like I have done for years) puts your valves in danger of getting burnt, as the crankcase gasses normally act to cool the combustion temp. 'course, if you run like I do (say 1000 miles max/year), it might take 100 years to burn those valves open
DOUBLE NOTE: running with egr shorted is technically illegal due to smog system being viewed as "modified". Also not a good thing for the planet, though that scenario is only in the low rpm idle situation. But on the flip side, you are using a resource (the energy invested in the rig) to the max, thus not wasting all the energy used to make the rig versus scrapping and loosing that energy investment (cradle to grave).
That's all the news that is fit to print
You can test the low rpm idle/egr scenario by whacking the egr valve with a screw driver handle. This usually allow the valve to close fully with resulting smoothing out of the engine idle.
In valve "stuck open" mode, you may be able to hear a whistle when you manually up the rpm at the carb/thorttle cable with ear to egr.
If all the above are evident, you can then "short out" the egr valve in the closed position by disconnecting the vacuum line at the top of the valve and plugging. Make sure to put a cover on the valve/vacuum line pipe so no needless debris get into the valve. NOTE: running in this condition (like I have done for years) puts your valves in danger of getting burnt, as the crankcase gasses normally act to cool the combustion temp. 'course, if you run like I do (say 1000 miles max/year), it might take 100 years to burn those valves open
DOUBLE NOTE: running with egr shorted is technically illegal due to smog system being viewed as "modified". Also not a good thing for the planet, though that scenario is only in the low rpm idle situation. But on the flip side, you are using a resource (the energy invested in the rig) to the max, thus not wasting all the energy used to make the rig versus scrapping and loosing that energy investment (cradle to grave).
That's all the news that is fit to print
4Cruisers
SILVER Star
Not yet, got hung up on replacing my U-joints and cleaning the driveshafts. The last one was a real bugger, just finished popping it out using my 20-ton shop press.
The EGR on a 62 is not related to crankcase fumes - that’s your PCV system. The EGR system dumps (mostly inert) exhaust gasses into the intake which provides reductions in cylinder pressure and temperature, by the inert gasses both absorbing heat and also displacing combustible oxygen in the combustion chamber, leading to reduced NOx formation (the intended purpose of EGR.)Kleatus: Yes, any leak in egr will lead to rough engine (at low rpm). At low rpm, the egr is closed, thus leak-by makes engine run lean (too much non-fueled fumes from crankcase). At high rpms, the egr is open (leaning out as designed) and has full crankcase vent and runs well (as designed).
You can test the low rpm idle/egr scenario by whacking the egr valve with a screw driver handle. This usually allow the valve to close fully with resulting smoothing out of the engine idle.
In valve "stuck open" mode, you may be able to hear a whistle when you manually up the rpm at the carb/thorttle cable with ear to egr.
If all the above are evident, you can then "short out" the egr valve in the closed position by disconnecting the vacuum line at the top of the valve and plugging. Make sure to put a cover on the valve/vacuum line pipe so no needless debris get into the valve. NOTE: running in this condition (like I have done for years) puts your valves in danger of getting burnt, as the crankcase gasses normally act to cool the combustion temp. 'course, if you run like I do (say 1000 miles max/year), it might take 100 years to burn those valves open
DOUBLE NOTE: running with egr shorted is technically illegal due to smog system being viewed as "modified". Also not a good thing for the planet, though that scenario is only in the low rpm idle situation. But on the flip side, you are using a resource (the energy invested in the rig) to the max, thus not wasting all the energy used to make the rig versus scrapping and loosing that energy investment (cradle to grave).
That's all the news that is fit to print
If the EGR valve is partially obstructed and held open by carbon build up, “shorting it out” as you describe will not fix the rough idle issue - it will only assure that it can’t open when it needs to. The EGR operation is also not dictated solely by RPM, but rather a combination of things - RPM, engine load (vacuum, throttle position), and coolant temperature for example.
Red66toy: True true. Thanks for corrections.
w/r shorting: should have clarified this. Trick is to whack top of correctly installed (all lines) egr valve w. screwdriver handle until whistling disappears (or, if you have a vacuum gauge hooked up, vacuum rises significantly).
Again, many thanks for straightening me out on errors above. Devil is in the details
w/r shorting: should have clarified this. Trick is to whack top of correctly installed (all lines) egr valve w. screwdriver handle until whistling disappears (or, if you have a vacuum gauge hooked up, vacuum rises significantly).
Again, many thanks for straightening me out on errors above. Devil is in the details
Not surprised I guessWell, I tried the untrasonic cleaner and I am extremely surprised at how much crap came off the outside and inside of this thing! I wish I had more before pictures because it was pretty nasty.
The water was black and all kinds of crusties in the bottom of the pan. This was with purple power cleaner. Maybe some different formula/type would be better? There was a very noticeable difference in the air leakage by blowing through it before and after ultrasonic cleaning. I need to investigate this further. Any other suggestions for cleaning medium?
