Where are you guys headed to this year? I swear one of these trips I need to come along.
CK5
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'91 K5 Four Wheel Camper
This is the build for my 1991 V1500 Blazer, AKA the K5.3. It started out life being sold to the U.S. Government with a 350 TBI/700r4/241 combo. 4 years with a 5.3/700r4 Combo and now moving to an 8.1L Vortec and NV4500 5-speed.
I hate that late gas mileage
Is it better in the morning?
Geeze. My phones aggressive auto correct in action.
Getting back to my exhaust leak/fuel economy issue. I was pretty sure it was the driver side manifold leaking at the head. I had already tightened up the exhaust flange to pipe and it free of any signs of leaks. At minimum the manifold needed to come off.
Remembering the last time I had to do this taking the manifold off from both the head and pipe was a giant pain in the ass. I figured since the pipe flange wasn’t leaking I would not take it apart. The problem is you can’t slide the manifold away the head enough to clear the studs. But if I leave the manifold to the pipe connection the manifold is mostly held where it needs to be but I need to pull the studs out.
So that’s what I did. I noticed some of the studs were not perfectly tight compared to the rest. But they all came out without a fuss. That allowed me to pry the manifold away from the head enough to pull the old fiber exhaust gaskets. Little razor action to clean up the residual and slide the new gasket in place. The only leak was from the #7 port at the upper rear corner.
Since this is the second time I’ve had to do gaskets and both were the fiber style I decided to go a different route this time and see if it works better. I ordered some Mahle multiple layer steel gaskets to try out.
New gasket slid right in. The studs went back in without too much issue. Overall it went way easier than trying to balance holding the manifold with one hand and get it over all the studs while making sure the gasket gets into position. I did fire the truck up and confirmed it’s quiet again. Finally. After it got some heat in it I retorqued all the nuts.
Next up fixing the broken hangers on the tailpipes.
Remembering the last time I had to do this taking the manifold off from both the head and pipe was a giant pain in the ass. I figured since the pipe flange wasn’t leaking I would not take it apart. The problem is you can’t slide the manifold away the head enough to clear the studs. But if I leave the manifold to the pipe connection the manifold is mostly held where it needs to be but I need to pull the studs out.
So that’s what I did. I noticed some of the studs were not perfectly tight compared to the rest. But they all came out without a fuss. That allowed me to pry the manifold away from the head enough to pull the old fiber exhaust gaskets. Little razor action to clean up the residual and slide the new gasket in place. The only leak was from the #7 port at the upper rear corner.
Since this is the second time I’ve had to do gaskets and both were the fiber style I decided to go a different route this time and see if it works better. I ordered some Mahle multiple layer steel gaskets to try out.
New gasket slid right in. The studs went back in without too much issue. Overall it went way easier than trying to balance holding the manifold with one hand and get it over all the studs while making sure the gasket gets into position. I did fire the truck up and confirmed it’s quiet again. Finally. After it got some heat in it I retorqued all the nuts.
Next up fixing the broken hangers on the tailpipes.
Tailpipe hangers fixed. Ultimately, the exhaust needs to be done again. I’ve got a muffler I know I blew a baffle out of, but the way it’s hung there aren’t any hangers mid way. I think it’s a big reason why the tailpipe hangers break and stresses out the flange connection at the manifold.
Since I don’t have a welder to repair the drivers side round rod hanger again I got a different style that works with a clamp. Took rubber isolator off of the one that broke and replaced the one on the other side that did break. Should be good for the summer.
I’m looking forward to the trip and seeing the mileage pick back up. That leak was no less than 10” upstream from the o2 sensor. It wasn’t as bad as previous leaks at the donut that caused it to go pig rich on that side and the truck really would not run well under a load. It should come right back up to the normal average.
Next up diagnosing why the speedometer won’t start moving until you get up to at least 25-30mph. Once you get past that speed it’s normal and accurate. But if you dip back below it just falls to zero again until you speed up. It does seem like the longer I drive the more normal it gets and works at lower speeds. I’ve scoped out the wiring and all looks good under the truck.
I think I might pop the vss sensor out when I’m under it next doing the oil change and nut-bolt check. I’m not sure if the tone ring inside the 241 is loose or what. Any ideas I’m open to suggestions.
Since I don’t have a welder to repair the drivers side round rod hanger again I got a different style that works with a clamp. Took rubber isolator off of the one that broke and replaced the one on the other side that did break. Should be good for the summer.
I’m looking forward to the trip and seeing the mileage pick back up. That leak was no less than 10” upstream from the o2 sensor. It wasn’t as bad as previous leaks at the donut that caused it to go pig rich on that side and the truck really would not run well under a load. It should come right back up to the normal average.
Next up diagnosing why the speedometer won’t start moving until you get up to at least 25-30mph. Once you get past that speed it’s normal and accurate. But if you dip back below it just falls to zero again until you speed up. It does seem like the longer I drive the more normal it gets and works at lower speeds. I’ve scoped out the wiring and all looks good under the truck.
I think I might pop the vss sensor out when I’m under it next doing the oil change and nut-bolt check. I’m not sure if the tone ring inside the 241 is loose or what. Any ideas I’m open to suggestions.
Have you driven long enough at low speed to see if the odometer still rolls? If so, it is the MPH pod.
I think the ball and socket, with springs on the studs, would work better than a fixed flange. At least for 4x4 that see trails. It would allow the the connection a small range of motion and some twist.
I’ve watched but not close enough. I’ll have to find some wide open empty parking lot to watch without worry of traffic. I do have another electric Speedo cluster if i need to try it.
The stock manifold to pipe connection is ok as long as it’s not the only thing holding the front half of the system up. I’m using the brass extra tall nuts on the studs and doubled them up to keep them from backing off. The side benefit is most of the threads are covered up by the nuts so they aren’t crusty to take off. Once those went in place they have held. No more blown donuts.
Is the vss an adjustable air gap style sensor? If so I'd bet the gap is too big to sense a signal til it gets some more speed to it.
It’s all factory 241 stuff. I don’t think there is any adjustment. The variable though is it’s happened since I had to swap the guts out of my old 241 to a new housing after BB. Though the problem didn’t start until a couple of years after the repaired tcase went back in. I don’t think the tone ring and move forwards or backwards on the shaft, but if I missed something on the reassembly which also included a sye conversion with a new shorter output shaft it could have something to do with it.
Liked for the good deal. Might dislike for passing up the H2’s.Welp it’s getting to the time of year to prep the big dog for our annual desert trip. First thing up is shoes. The Cepeks served their purpose well. The tires worked good on dirt, rocks and snow. Road manners were pretty solid too. They are pretty chewed up from three years of use. Wear was consistent at least.
Here is where my problem came in for replacement I’m still rolling on 16” wheels. Selection of 16’s anymore sucks if you’ve looked lately. So I went on the hunt for some 17” wheels. I almost pulled the trigger set of H2 wheels for $650. But as I found those I found a set of American Racing Baja wheels in black and had some 315/75 17 Goodyear Duratrac on them. Two were new and the other three had decent tread left. Price was $1000 for the 5.
I picked them up Friday and threw them on the truck. Wheels cleaned up pretty easy, no curb or rock rash. The wheels alone were worth the price compared to buying new.
I’ve got another exhaust leak to fix before the trip, oil change, grease job and general nut/bolt check. I’m pretty sure the leak is at the head so new gaskets are in order. I’ve torqued the studs cold and hot and still have the leak. It’s enough it’s throwing off the o2 sensor and fuel trims as the mileage is pretty consistent in the 11pm range.
The trip is in June so I’ve got time to knock it all out.
Either way, the new setup looks good.
The h2’s would have been cool but I just could
Not beat the price. I will keep my eye out for some cheap h2 down the road but it’s going to be a while.
Got all the maintenance done today. I did pull the vss sensor. Looked fine. Tone ring is locked in place like it should. I haven’t driven it yet but I’ll watch when I do. I’ll order a new sensor if it does act up.
