I picked up a 2000 Blazer with various issues. After flushing the dexcool and what looked like mud out of the cooling system (two seperate flush cycles - and still need a third as the new coolant has a dirty look to it), changing the oil, replacing the heater core (yeesh don't sign me up for that again), and replacing the front shocks, seems to be overall a decent (ish) ride. Not overheating and not losing any coolant.

Remaining issues that I am looking for feedback on:

1. 2WD/4WD lights are sporadic. Most of the time they are off altogther, but out of the blue sometimes they will come on (2WD). Sometimes I can get it into 4WD Hi and/or Low and back to 2WD, sometimes no response at all. When it does work I am able to hear a very loud Hiss when going from 4WD High to 2WD.

2. Horn sometimes works - suspect wiring but will be investigating further once other issues squared away.

3. Transmission was at least 1 Quart Low when I got it. Added 1 Quart of Valvolean ATF high mileage treatment and still was under the hash marks after running up and down the road to heat the tranny up. Added 1/2 quart castrol fluid to it and it was at the proper level.

Transmissions Symptoms:
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A. At about 1450 RPM at about 50 MPH felt like I was riding the shoulder wake up ridges on the side of the road. It would come and go, but would be fairly consistant. After adding tranny fluid very rare to occur and only for second if it does. Seems to only occur in Overdrive

B. At the normal shift points, it would feel like sometimes motor would rev up and down and maybe it was slipping. Not sure as I couldn't really tell if it was a motor issue or the transmission. Still occassionally does this, but seems to be smoothing out the more I drive it around after adding the fluid.

C. Fluid on the stick looks OK. Does not look burnt, has proper "smell" and is very reddish / pink. Now it may have been flushed or changed prior to me getting the vehicle so not sure.

D. Even though when the fluid was added it appeared at the proper levels (checked 3 times on flat surface with my son to confirm), it now seems it might be slightly over full. Is that possible? What can account for the level showing high now even though it wasn't before or is is it just a temp difference in the fluid maybe?

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I have new plugs, wires, and rotor button, but not sure I want to put those in if I have bigger issues. Could bad / worn plugs and wires cause the transmissions symptoms I am seeing? Are they tied together? Are there vacuum lines I need to trace out specifically to do with the transmission or is it all electronic now? I know I have found a few vacuum lines that are just falling apart.

Any advice helpful. So far, I can sell it as is for at least what I have in it, but would prefer to drive it as a daily drive for as long as possible and if I can get a year or two out of it, I would be happy.

Should I do a fluid exchange on the transmission (not a back flush or pressurized exchange) by disconnecting one of the tranny lines and pumping a few quarts and and adding back a few quarts? The goal would be to do a gradual "improvement" to the current fluid over time, not necessarily a full Exchange of old to new at once. Finally, what should I use in the transmission for a vehicle with over 200K miles on it?

Thanks for any advice in advance!

 

Update: After doing some looking through other forums / searches / etc I am going to start with re-flushing the system and changing out the radiator doing a thorough flush of the motor (well as thorough as I can) with the Radiator off of the car (i.e - take out the thermostat and put pressurized water through the system from every direction I can until nothing but clear water comes out again).

I suspect either I have a transmission / oil to coolant leak -OR- there is just so much crap stuck in the current radiator that I just need to change it. Either way can't hurt. For $90.00 it is worth a shot. I still have the intake manifold gasket set and bolts which will probably be my next step, but was really hoping it didn't need it done. As I said, it is not overheating and is not noticeably loosing coolant, but the seemingly higher level of transmission fluid than when I initially topped it off has me suspecting of the cooler lines maybe leaking - although there is no noticeable sign of that on the stick.

Either way, while changing the radiator I plan to do a fluid swap on the transmission with Valvoline Maxlife and a bottle of Lucas transmission treatment as well.

Looking for any additional thoughts /advice before moving forward? Assuming the above procedure fixes the brown radiator fluid issue and the transmission issues resolve with the fluid swap, I will take it in to a shop and get them to do a filter / fluid change (I know I can do it at home, but the several hours of me laying on a gravel driveway is not something I am looking forward to)

 

You've got a head scratcher there.

It sounds like the coolant was definitely neglected on that one. That would be the 100K mile/10 year coolant, that wasn't changed or maintained.

Pink, unburnt transmission fluid at 16 years and over 200K miles isn't neglected, original fluid. It's a sign that someone either did maintenance or repairs. Since there's other evidence of neglected maintenance, I'd suspect repairs, and that's actually a good thing for you.

I never just "swap fluid" by any method, especially not the special machine that pumps out the old and pumps in the new for a more "complete" flush and replacement. I always drop the pan, replace the filter and refill. I know it doesn't replace all the fluid, but it gets a lot of it, and it gets a fresh filter in there. I also clean the valve body, and if the design allows for further inspection by easily removing the valve body, I dig deeper and check the condition on any easily accessible seals and o-rings in the thing. For yours, I'd also be looking really close for tool marks indicating a "rebuild" or internal repair work on the unit. If it's repaired, and all the seals and rubber bits appear to be relatively fresh and flexible, I'd keep it on a 30K mile filter/fluid change and use the "high mileage" fluid. I strongly suspect that's what you have.

If the seals and other rubber bits that are exposed or easily reached for inspection look older and hardened, more "original" rather than repaired/replaced, I'd most likely stick with "conventional" fluid and hope it doesn't leak.

Max Life is a synthetic (or at least semi-synthetic) fluid, and if your seals are really old have cracks that are filled with varnish, gunk and byproducts from conventional fluid, it can wash out the "gunk", exposing the cracks as leaks. It doesn't cause the leaks, the leaks were already there. It just cleans out the gunk that was masking/plugging the leaks.

With regard to the intake manifold gaskets, look closely between the aluminum of the lower manifold and the plastic of the valve covers. You'll see a bit of the intake manifold gasket there, as well as the valve cover gasket. If the valve cover gasket is blue, and the lower intake manifold gasket looks like black rubber from front to back, it already has the Fel-Pro "Perma-dry" gasket set. If there's metal (either shiny silver or perhaps slightly rusty metal) showing, along with black rubber for the intake manifold gasket, that's the later, upgraded GM or AC-Delco gasket (or a metal framed knock-off). In either case, leave it alone.

If you see plastic between the lower manifold and the head (usually blue or aqua color, but sometimes other colors as well), you have a plastic framed gasket that's either already leaking or will leak. I'd replace those. Also, if it still has a plastic dizzy, you might want to spring the $40 or so for a cheap, Chinese metal frame dizzy (Skip White seems to be the favorite on this forum). You have to pull the dizzy off to change the lower intake gaskets, so it's a good time to put a better one on. The Fel-Pro "Perma-Dry Plus" gasket set is the one to use if you have plastic lower intake gaskets now.

 

Update 2: I replaced the radiator this evening. I let it sit for a while before I started the process and thought it had depressurized, but when I took the cap off it vomited (literally what it smelled and looked like) fluid everywhere. Now I have to rinse off engine compartment as anywhere the liquid was and dried is brown. Looks like I took it out through the local 4 wheel trails....

Anyway - just finished that procedure (a bit tight without removing the fan) and waiting for it to cool down from the test drive to check the fluid color. Interesting part is when I pulled the transmissions lines loose, I lost absolutely no fluid at all. The oil lines I did lose about a bit.

I pull nearly every hose off I could and the Thermostat housing and rinsed everything from every direction I could find until I got plain clear water out of the system.

Tomorrow I will hopefully have time to do some fluid change on the transmission by disconnecting the top transmission line and connecting a fitting with a clear tube on it going to a bucket. That way I can catch the expelled fluid in a clean controlled container and take to the trans shop when I have them do the filter change.

I also was able to feel some of the shimmy while in park which may mean it is an issue with the motor and not the transmission. I can get it to occur at just under 2000 RPMS in idle and while it isn't bad, I can sense it may cause the symptoms I am feeling while driving under load. In addition when changing the radiator I found the Secondary Air Generator (Is that what it is called) had a big line to it that was cut. Now I need to find out if this vehicle had California Emissions and see if that thing is needed the way it is setup now. It may be the Engine control system are just expecting something that isn't there.

Anyway I will post an update tomorrow. Good night and thanks again for your help!

 

Morning Update:

Drove it about 30 miles now with new radiator and everything is still connected and no leaks. Checked the fluid and nice bright green. So either I was indeed mixing fluids in one or both cooler lines -or- the old Radiator was so gunked up the flushes just didn't get it all.

Transmission is still showing maybe half a quart (1/4" over on the stick) idling after driving for the 30 miles so I need to evacuate some fluid which I will do tonight via the clear hose to fitting on top transmission outlet on the radiator.

Shudder is still there and very noticeable - only in Overdrive under load at about 1500 RPMS. Hoping removing some fluid, adding the Lucas in and a few quarts of fresh fluid at the proper level may help with that issue. The other reason to remove some fluid is so I can get a good look at it besides what I see on the stick. If all goes according to plan I will be swapping 1/4 to 1/2 the fluid this evening.

I will update after I do the above, but good news is that radiator lost no coolant on the drive into town and is holding pressure on both upper and lower hoses so it appears for now I don't have a major issue with the cooling system. Temps stayed good.

One last note. This vehicle is an enigma. The cooling system was obviously severely neglected and I cannot pull up any service records on it, but I can tell there is a new rack / pinion, drivers side ball joints, inner tie rods (both sides), brand new tires (priced them at $700 for the set), good brakes, new ABS unit, new alternator, new battery, and a few other items I noticed here and there. Seems like someone somewhere did at least try to maintain the vehicle before I acquired it.

Once I determine if the Transmission issues can be resolved, I will move on to the 4WD and then once that is done the truck should be back to full functionality again.

 

How are the motor mounts? And the front diff mounts?

Motor mounts on this engine are notoriously bad. Rubber mounts last a few years at best. A bad mount on the left side can cause some excessive vibration under load.

 

Final Update:
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Good news: the shimmy is gone..

Bad news: so are drive and reverse after about a minute of running. Fluid is full.

Old fluid looks like it has a couple of layers in it looking in the 5 Gallon bucket I have it in. Clear layer on top (1/4" - Water??), glittery dark red / not brown but definitely dark layer below that, and thicker layer down below that.

I suspect I was getting trans / radiator mixing in the radiator cooler and based on the "glitter" I see in the fluid that I pumped out we definitely have damage to the trans / torque converter.

After driving for a 30 seconds to a minute, I can no longer get reverse to engage. Sometimes drive will re-engage. Turning it off for a minute and then starting it again, I can get reverse to engage, but once I take it back out of reverse and try to put it back in it will not re-engage. Additionally rattling metallic clinking sounds now are apparent.

So, good news is this happened in my driveway and I am only out the cost of the fuild. Bad news I am out the cost of the fluid and am now looking at a dead tranny.

So....... choices. Save this 00 blazer for spare parts for the 02 we just put a new motor in. The 00 has the following when I bought it: brand new set of tires, new battery, new alternator, newish ABS unit. I paid about $1000.00 for it and those parts alone are worth what I paid. Has lots of other good parts on it as well. That is one choice.

Choice 2: Go to a pick a parts and spend a day pulling a transmission out of a used vehicle for $200.00. Not my first choice since I have no idea of why the vehicle is there to begin with.

Choice 3: Order a used tranny from a local parts place that "says it is a good working tansmission" and install myself over a weekend or have someone do it for me and pay them. For the value of the vehicle this seems like the most logical choice, but those are still running $500 (ish).

Choice 4: Order a used tranny of Ebay for $300.00 (ish) and put in myself or pay someone to di it.

Choice 5: Purchase a reman from online or locally, but seems the cost of those is well past the value of the vehicle.

I am inclined to go with #3 or #4. I don't suppose there is anyone in the Virgina area that has a good used 4x4 tranny they want to let go for cheap is there . I would probably trust people here before I would most others.

Motor in the one I have is good (may still need intake done, but don't think so as radiator fluid is changing a little bit, but that may be just due to the other previous crap working its way through the system).

Looking for advice from others. I would love to get this fixed up, but I am about $1250.00 into this vehicle and want to walk away before I put more into it than it is worth doing.

 

The transmission in these things is widely available on the used parts market. TO add to your choices, check Car-Part.com--Used Auto Parts Market

I just looked, and reman units on there look to be around $1,000 +/-, but I didn't check down the price range too far. There are so many for that one, there's like 60+ pages listed with prices, and 95 pages total listed. Used units with "tested good" start at $150, and are common in the $175-$200 range. Usually "tested good" units have a short (30 day to 90 day) warranty from the seller.

That site can be a little annoying because some of the parts listed are no longer available when you call. But I generally find something with fewer than 10 phone calls, usually in the first 3 or 4 calls.

Let me close with advice, if you want the "new tires" to stay new, you should get the thing up on jack stands and get the tires off the ground. It doesn't take too many weeks for tires to get "the shakes" when they are on the ground and loaded.

 

Not trying to pile on. But if you replace your transmission you'll need to get another transmission cooler. There's no way to get all the metal particles, glitter, out of your cooler and it will kill your new transmission. Since your radiator is new I'd get an aftermarket transmission cooler.

 

Good Evening -

So I decided to take a chance and replace the filter. The magnet looked like a chia pet (I will post pictures tomorrow). After added a gallon of store brand dex merc fluid back and making sure level is right, I now have revers, D1 and D2.

I got it into D3 and even OD once, but lost it (engine just revs).

When I changed out the filter, found the old one was completely plugged up I am assuming preventing fluid flow to the relevant parts of the transmission.

So here is my question - Is there a possibility that:

A - The Valvoline Maxlife Transmax fluid was / is not compatible with this transmission (says it is)?

B - I have a simple problem with a shift solenoid?

I think I know the answer to both of these as in reading forums in that no D3 and OD usually means worn clutch packs and a rebuild.

Any thoughts on anything else I might check?

For anyone else needing to change fluid / filter on 2000 Blazer - I did NOT have to drop the crossmember, just loosed the bolts on the transmission mount and jacked it up about 1/4" which gave clearance to maneuver the pan in and out of position.

A second note is that apparently the filter CAN be so clogged up that it can cause shifting into gear issues. More details on my experience tomorrow. For now it is time to go to sleep and hopefully not dream about that missing transmission pan bolt that it tool forever to find......