FAQ: High Mile Club - Wear/Repair Reports

That's what they all say..............

Flo, I'd get that master cylinder fixed as soon as you can. It's not that expensive, and it will only get worse the longer you wait. Eventually it will go out all-of-a-sudden (I've had this happen on a previous car), and you will have a big problem that could result in an accident. Remember, the most important system on the car isn't the engine or the transmission, it's the brakes.

How many miles on the master cyl? My original is still working at 220k.

florence_x wrote:

My master cylinder is shot (leaking brake fluid), but otherwise I don't really have any huge problems with my '95 Riv. Since I'm not exactly rollin' in dough right now, I tend to just keep a few bottles of brake fluid handy so I can top it off when the brake light starts to go off.

Other than that, (3) smaller, slightly-more-annoying problems: need a new thermostat, coolant sensor is shot (light is always on, level is always fine), and my passenger side window's motor might be crapping out.

When the car's title was transferred to me, she needed new brakes/tires/etc., but my dad hadn't been driving it. Otherwise, she runs like a dream and regardless of the problems I'll have this car forever.

'95 love!

Coolant sensor: IIRC usually those just need to be cleaned. If you drain and remove the reservoir for some reason try cleaning the sensor with soap (Dawn or other dishliquid) and water, rinse well. I think there was a post on this, and I think there were 2 types of sensors.
Master Cylinder: a good junkyard hand can spot a recently replaced MC from far away, and the GM MCs were pretty standard across car lines by size (the Riv uses a common ATE or Bendix master cylinder). Might want to think about getting a junkyard one if you know such a good junkyard hand -- people don't junk their cars over MCs and it's not uncommon to have cars come in to a yard with relatively new MCs, alternators, shocks, and other wear parts.
Thermostat: sure you saw the other threads on these
Window motor: One of those DIY jobs that can be a pain. A Cardone reman motor is not too pricey though. The easy way out might be to get a whole regularot assembly with good motor from a donor car, but I am not sure how likely that is -- maybe thing to do is call/email ed morad (moradpartscompany.com) - the remans are $40 or so, seems that a pull ought to run $5 to $20 depending.

ha ha my 95 has 213,000 and my girlfriends 95 has 240,000! They both run great! I wonder if anyone on here has over 300,000

albertj wrote:

Coolant sensor: IIRC usually those just need to be cleaned. If you drain and remove the reservoir for some reason try cleaning the sensor with soap (Dawn or other dishliquid) and water, rinse well. I think there was a post on this, and I think there were 2 types of sensors.

The '95s had the low-coolant sensor in the recovery bottle?
Mine is halfway down the RH radiator tank (though if you drain the radiator, it does go in & out very easily - just don't put too much pressure on the plastic ears...)

From what I've read in my new service manual (thanks rick!) They are in the rad on the 95 (no pic with it) but the book also shows a sensor located on the bottom of the recovery tank. I'm not sure which it is either. My low level light will comes on everytime I start the car when its warm but not when its cold even tho the level is always fine. Started doing it about a month after I replaced the radiator. A new sensor shows for $36 dollars on rockauto but if I can just clean it that's even better. Can anyone weigh in with more info?
Oh and btw AA my master cylinder crapped out and needed replacing at 62,000 miles. The car sat at a dealer for a few months and I think with these cars all it takes is a few months of sitting and the seal will leak.

Derek wrote:

From what I've read in my new service manual (thanks rick!) They are in the rad on the 95 (no pic with it) but the book also shows a sensor located on the bottom of the recovery tank

Derek, I just looked in my own manual, and I suspect that you and Albert are looking at the "VIN C" sensor & surge tank - the one for the V8 Aurora...

Here's a photo of a Riviera side tank, courtesy of Abaddon, that shows the location for the typical Riviera sensor with a little screw-plug in it. If you replaced your radiator, there should have been a couple of wires and an oblong plastic sensor where the white circle is:




The fact that your light never comes on cold, and always comes on hot, makes me think that you didn't transfer the sensor over to the new radiator (or left the connector off) and the PCM doesn't check the sensor unless the coolant is over a certain temp... the way the oil-level sensor has a bunch of time & temp parameters that have to be met to actually turn that light on.

Eldo wrote:

Derek wrote:

From what I've read in my new service manual (thanks rick!) They are in the rad on the 95 (no pic with it) but the book also shows a sensor located on the bottom of the recovery tank

Derek, I just looked in my own manual, and I suspect that you and Albert are looking at the "VIN C" sensor & surge tank - the one for the V8 Aurora...

Here's a photo of a Riviera side tank, courtesy of Abaddon, that shows the location for the typical Riviera sensor with a little screw-plug in it. If you replaced your radiator, there should have been a couple of wires and an oblong plastic sensor where the white circle is:




The fact that your light never comes on cold, and always comes on hot, makes me think that you didn't transfer the sensor over to the new radiator (or left the connector off) and the PCM doesn't check the sensor unless the coolant is over a certain temp... the way the oil-level sensor has a bunch of time & temp parameters that have to be met to actually turn that light on.

As Eldo states, the VIN C sensor is in the tank, VIN 1 is in radiator. Pardon me while I scrape the egg off my face. I had been pulling spares off an Aurora at the pick n pull and was going by memory, which I should not have done. The sensor is pictured on p. 6-391 of the '98 G platform service manual. They must have been paying the tech writers by the page, because the illustration is repeated for installation and removal which really wasn't needed although it makes the instructions easy to spot.

Albertj


the VIN 1 sensor

Well following Eldos suggestion I went and checked and sure enough the low coolant sensor is in the rad on the passenger side about halfway down. The sensor was definitely installed and connected so I guess I'm back to clean the existing or replace with new. As far as meeting the parameters to turn the light on I assume a non-working sensor would be about the same as one that's not installed which could be why its only on when I start the car warm.

OK New question: are motor/transmission mounts basically a 100,000-mile maintenance item?

I am about to install my second set. At appx. 240,000+ miles.

Do tell.

I have original mounts at 223k. However, the rear badly needs replaced!

AA wrote:

I have original mounts at 223k. However, the rear badly needs replaced!

I am thinking the time to replace mounts is when there's visible cracking on the rubber, not at complete failure. Mine (with ~120 K mi on thm) have cracking on the rubber and are sagging somewhat.

albertj wrote:

OK New question: are motor/transmission mounts basically a 100,000-mile maintenance item?

I am about to install my second set. At appx. 240,000+ miles.

Do tell.

If I were you, I'd do what Scott did and fill the open cavities of the new mounts with window weld and see how they hold up then since you're fixin' to do it anyway. I'm gonna do that myself.

turtleman wrote:

albertj wrote:

OK New question: are motor/transmission mounts basically a 100,000-mile maintenance item?

I am about to install my second set. At appx. 240,000+ miles.

Do tell.

If I were you, I'd do what Scott did and fill the open cavities of the new mounts with window weld and see how they hold up then since you're fixin' to do it anyway. I'm gonna do that myself.

I was thinking about that but *really* don't want the vibration at idle in the cabin and had not read from Scott whether the filled mounts do that.

I am keeping the old mounts to refill with lo durometer urethane (window weld).

Do you have any info about the vibration thing?

Quote :

I am thinking the time to replace mounts is when there's visible cracking on the rubber, not at complete failure. Mine (with ~120 K mi on thm) have cracking on the rubber and are sagging somewhat.

When I had the transmission rebuilt at 151k miles, the unit was removed and installed at least 3 times. I would assume if any of the mounts were bad at that point, AAMCO would have at least informed me of their condition and given the option to replace. I don't doubt they were cracking or sagging, but I do know there was some life left in them at that point. If I had to guess, the mounts were engineered for 150k miles minimum, to match the life expectancy of the rest of the car.

My Riv has finally reached the 100k mile mark. Still runs like brand new.

just bought my white with tan interior 1998 currently it has 173k on it with tranny rebuilt about 40k ago because it was sitting i have so far replaced all of the brake lines and had the gas lines replaced from fuel filter to the bendex (400 for the lines) it looks like it is going to need a camshaft pos sensor but that should be easy to take care of and it needs paint badly NY winters what can i tell ya lol

Welcome Adam. I'm just down the road in Cheektowaga. I also have a white w/tan interior, but mine is a 95.

albertj wrote:

turtleman wrote:

albertj wrote:

OK New question: are motor/transmission mounts basically a 100,000-mile maintenance item?

I am about to install my second set. At appx. 240,000+ miles.

Do tell.

If I were you, I'd do what Scott did and fill the open cavities of the new mounts with window weld and see how they hold up then since you're fixin' to do it anyway. I'm gonna do that myself.

I was thinking about that but *really* don't want the vibration at idle in the cabin and had not read from Scott whether the filled mounts do that.

I am keeping the old mounts to refill with lo durometer urethane (window weld).

Do you have any info about the vibration thing?

Update

The old transmisson mounts were IMHO too chewed to mess with. I chukked them.

I decided not to fill the new ones - their rubber is thicker than the old ones and now I know why the OE ones were designed as they were. The new mounts drive better but sound worse - they bring back (albeit ever so slightly) the famous Buick Six "humpmobile" vibration at idle... the tradeoff is worth it for the drive though.

So I am glad I did not fill the new ones. I wish there was a way to use liquid filled mounts, that'd take care of the "humpmobile" buzz.

adam14212 wrote:

just bought my white with tan interior 1998 currently it has 173k on it with tranny rebuilt about 40k ago because it was sitting i have so far replaced all of the brake lines and had the gas lines replaced from fuel filter to the bendex (400 for the lines) it looks like it is going to need a camshaft pos sensor but that should be easy to take care of and it needs paint badly NY winters what can i tell ya lol

cam sensor is easy, crank sensor requires patience and a steady hand...

258,000+ Miles

Blown head gasket.

I have zero ability to fix myself. Shop estimates $1500 to repair, ($1000 is in labor) and is suggesting that I replace the engine with reman or salvage. I am not selling the car. Thought I would ask for opinions from the group.

I guess it would depend on if the engine has any other problems and how it runs. Probably could find an engine with around 120,000 for around $1500, but then you still have the cost of labor to put it in and other variables. Don't know what reman ones go for. Personally for me if the car ran fine otherwise. I'd probably just opt to do the headgaskets.

There is no way you can replace an entire engine for the same cost as installing new head gaskets. Like Chris suggests above, if your current engine is healthy aside from heads gaskets, then just fix whats broken.

Thanks for your thoughts. I realize that a reman engine will be more. My thinking is that with almost 260,000 miles, even if it is running OK now, there is no telling how much life is left. I may take the opportunity to swap in a Gen V, ported TB & LIM and smaller pulley.

sburch23 wrote:

Thanks for your thoughts. I realize that a reman engine will be more. My thinking is that with almost 260,000 miles, even if it is running OK now, there is no telling how much life is left. I may take the opportunity to swap in a Gen V, ported TB & LIM and smaller pulley.

Actually you *can* tell how much life is left - if the engine is not making funny noises (valve train chatter, squeaky bearings/pulleys, whatever) just do a leak-down test! The amount of time it takes for the cylinders to leak down pressure will give you a very good guess as to how worn the engine is, assuming everything else is maintained and wearing normally.

Here are the details mostly from

http://www.mobiloil.com/USA-English/MotorOil/Car_Care/DIY/Engine_Leakdown_Test.aspx

the Mobil article is nicely written but I think the person who did the final edit may never done a leak-down test and for whatever reason left out a lot of important detail. To do the test yourself you really need to read

http://www.carcraft.com/techarticles/116_0406_cylinder_leakdown_tester/index.html

To build your own tester you might/should read

http://www.motorcycleproject.com/motorcycle/text/leakdown.html


I copied a snippet of the Mobil article below, though, because it gets the basics across for people who are curious about a leak-down test although they may never actually do one. I also edited it a little for clarity and to put in details they really should have left into a "general" article on this topic IMHO.

-----begin quote--------------

What is a leakdown test?

A leakdown test is a compression test in reverse. Instead of measuring the ability of the engine to create pressure, compressed air is introduced into the cylinder through the spark plug hole. One gauge on the tester measures the pressure of the air entering into the cylinder and the other measures the percentage of the air escaping—or leaking from the cylinder. The loss percentage will indicate the condition of the cylinder and overall condition of the engine.

How to do it - Top Dead Center

The first step is to ensure the engine is warm. Then, since you will be pumping air into the engine, leave all the spark plugs in except for the cylinder you're testing. Before sending air into the engine, the cylinder being tested must be placed at top dead center. The piston must be at the top of its travel. The intake and exhaust valves must be closed. When the air is compressed into the cylinder, the leakdown tester will measure any loss of air escaping past valves or piston rings. If the cylinder is not at top dead center, air escaping past an open valve will give a false reading by leaking down.

Reading Results

No engine will have perfect sealing with zero percentage loss. Five to 10 percent loss indicates an engine in great to good running order. However, in supercharged and turbocharged engines, they usually have relatively larger ring end gaps so 15-20 percent is not bad in that case. For a normally aspirated engine, if it's between 10 and 20 percent it can still run okay, but it’ll be time to keep an eye (or ear) on things. Above 20 percent loss and it may be time for a teardown and rebuild. Thirty percent? Major problems. The percent of leakage should also be consistent across the cylinders. Any great differences indicate a problem in that cylinder. More important than the percent loss is where the loss is coming from. Actually it's not too hard to tell although you might need a buddy to help.. While one of you pumps air in thru the tester, the other one listens around. If you can hear a hissing sound coming from the valve cover breather hole or from the dipstick tube, then the air is escaping past the rings. If you prop open the throttle blade(s) and hear that same hissing sound, then the pressure is leaking past the intake valve (yeah you will have to take the MAF off most likely so run the test first and if your nums are 20 percent or more leak *then* consider taking off the MAF). If the air is escaping past the exhaust valve, you might well be able to hear the air even as far back as the tailpipe.

------------------end quote----------------

Thinking about it, if you are under 35% or so and the leakage from cylinder to cylinder is less that 10% different on the SC 3800 engine -- you're probably OK. Those of you who have done leak-downs on your engines please chime in. Closing comment - it is *entirely* possible that a well maintained SC 3800 engine will go well past a quarter million miles. You really have to test/measure in order to figure out if there's really an issue.

Albertj