drtidmore

I would politely disagree. Mobil 1 was introduced in 1974 and I started using it shortly thereafter in all my cars. I did change from Mobil 1 over to Pennzoil once they introduced their full synthetic (based on the lubricant that they developed for the space shuttle main engine turbo pumps). Yes, that first gen of synthetic used a petroleum-based carrier fluid, but ALL the lubricating and viscosity related components were synthetic. I have had no issues with oil leaks that would not have appeared regardless (dried out oil pan gaskets, etc) and I have had the opportunity to pull open a couple of the engines after many miles and have always been amazed at how damned clean and pristine they look inside. The big advantage with synthetics OVER conventional oil is synthetic's lubrication molecules can handle a LOT more heat without their lubrication properties deteriorating and the fact that it does not sludge up an engine. FULL synthetic oils have simply replaced the petroleum-based carrier fluid with a fully synthetic fluid. This does not really change the lubricant's ability to do its job, but it means that NO fossil fuel was needed or used. Yes, synthetic oil is expensive but I can still hear my mechanical engineer dad saying, "oil is cheap, engines aren't" and this applies even with the price of synthetic oils.

Yes, that would be simpler than the headlights. I run my fog lights full time as running lights and have since the car was new. I did upgrade the fogs to LEDs once a suitable LED came to market as I had replaced fog light bulbs so many times of the years that I long ago lost count.

Hopefully it did NOT come across like I was condoning 230 as acceptable, but rather pointing out that GM set the high speed cooling fan cut-in at 230 due to the engine's specs. I am all in on running at cooler temps as I have mine setup with a 170F thermostat and the cooling fans set to kick to high at 180 and not return to low until 170.

The short answer is NO! The software IS in the BCM for twilight sentinel but it is not quite that simple. The mentioned headlight switch with the TW slide is the first needed item and then the wiring from that slide pot into the BCM. Then a bit of custom hardware to enable the popup doors and headlights to operate needs to be added (a few relays) under the BCM control. I did investigate doing this exact mod a number of years ago, but it was one of those things that never made it out of mind, into the Reatta. The Reatta is the ONLY car I have owned since the late 70s that did NOT have Twilight Sentinel so I do miss that little bit of automation. Understand that this is NOT a plug and play mod!

http://www.autozone.com/ignition-tune-up-and-routine-maintenance/ignition-coil/duralast-ignition-coil/367748_576410_17367 http://www.autozone.com/ignition-tune-up-and-routine-maintenance/ignition-control-module/duralast-ignition-control-module/18730_728908_1343 Notice that they even go so far as to state in the description on the ICM that the parts are engineered and manufactured by Wells Electronics. If you have not already replaced the plug wires, now would be a good time to do so along with new iridium plugs.

They private label it under their store brand Duralast. When you open either up, the instructions are pure Wells Electronics.

The specific coil that you purchased is something of an unknown other than RockAuto selling it as proper. The vendor website states "OEM design and Quality" and while that may sound comforting, that could be misleading. The original Magnavox "OEM" design has a checkered history. Most of the aftermarket Magnavox style parts are of the same design as the original and with that all the inherent weaknesses. New in of itself is not necessarily better! FYI, both the coil pack and the associated ignition control module (ICM) underneath should be replaced together as a failure in coil most definitely can damage the ICM . Wells Electronics did a complete re-engineering of the Magnavox style ICM and coil pack and the change is pretty phenomenal. I know that the conventional wisdom is to swap out the Magnavox setup for the later designed Delco setup with the 3 individual coil pack, different ICM and the proper mounting bracket). This is a sound strategy. However it is NOT the only solution. The Wells Electronics version of the Magnavox design (sold thru Autozone) incorporates even more modern electronics than the Delco and as a result starts MUCH quicker (1/3 rev) and under more extreme conditions. Of course you are still stuck with the single, replace it all, coil setup. Again, I am NOT knocking the Delco setup as it was a huge improvement over the original Magnavox and you really can't go wrong with the swap over but the difference that the Wells setup delivered on my Reatta was profound. Starting my Reatta had never been an issue, taking a couple of so revs to fire but now I just basically bump the starter and it is off and running. Again, Wells did a complete redesign of both the coil pack and the ICM so while the single pack design is maintained, the rest of the setup is definitely NOT the OEM Magnavox design.

Pretty much the ENTIRE 440T4! The 440T4 origins are the TM125 3 speed which was GMs 1st transverse FWD transaxle and the engines it was designed for (ie early 80s) were LOW HP, low torque. The 440T4 more or less took the TM125 and grafted on a 4th clutch to provide an overdrive gear. I could write a dissertation on the weak points on the 440T4 when trying to drive more HP and torque thru it. It was NOT a bad design, just one without a lot of reserve strength. Mild supercharging the pre-Series I engine has been fairly successful against the 440T4 but such pushes the stock 440T4 transmission to the very edge of the design. In the pre-Series I SC engine used on the Pontiac GP, GM got away with the stock 440T4 other than beefing up the final drive section and the drive shafts/CV joints. The 4T60E began the effort of ongoing upgrades to the design over the years to keep pace with the ever increasing outputs of the various engines that GM mated to the design. The final 2003+ 4T65E-HD was a fairly robust transmission even against the vastly more powerful LS series V8 and Series III SC 3800. By the time 4T65E production ended , GM had redesigned and beefed up everything about the old 440T4 design, but at the same time, the family heritage was strong and as has been noted, it IS possible, with some effort, to transplant the mechanical heart of the 2003+ 4T65E into a 440T4 housing while maintaining the 440T4 purely hydraulic valve body and so no need to deal with the issue of electronic controls on the 4T60E/65E transmission.

I suspect that the previous owner confused the formal designation of the engine vs the fact that the LN3 (introduced in 88) was a major redesign of the venerable Buick 3.8 liter V6 engine and therefore he may have thought that the pre-LN3 were series 1 and the LN3 was series 2. Regardless, 88-90 used the LN3 engine and that engine did NOT have a "series" designation but is very closely related to the Series 1 so it came to be known as the pre-Series1 engine. The major change that the Series 1 brought was 5 more HP thanks mainly to the tuned air intake plenum. The similarity between the pre-Series 1 and Series 1 is SO close that you can bolt on the Series 1 supercharger with no change to the heads or the engine (the ECM will have to be recalibrated however). Many Series 1 engines developed issues with the new thermoplastic, tuned intake plenum warping over time, so personally I prefer the pre-series 1 engine.

There are a LOT of variables that impact the air vent temp, but it is a good rule of thumb that you are going to get, best case, 25F cooler air OUT of the vents as compared to the air going INTO the evaporator (ie the interior temp). So, if the interior temp is say 100F, you can expect 75F vent temp and if the interior is 75F you will get 50F vent temps typically. You have to set the AC to MAX COOL, interior getting nice and crisp and at highway speeds to get the vent temp to its lowest. About the best you can expect as an end point is in the lower 40s / upper 30s even though the evaporator itself may well be running around 32F. Assuming you are running everything factory, understand that the engine cooling fans, which also cool the A/C condenser run ONLY in half speed until the engine coolant temp is about 230F and that usually means that the evaporator is NOT able to adequately condense the A/C refrigerant so the cooling capacity of the system is degraded until you get some forward velocity so that the airflow over the condenser improves. Several of us have modified our Reatta's engine cooling fan operation to run at high speed full time or to switch to high speed at lower engine temps so as to provide better summer, stop and go A/C performance, not to mention lower transmission temps (the engine itself, per a GM engine designer, is happy as a lark at 230F). Just because you don't think the A/C is cooling adequately in stop and go summer heat does not mean there is an issue with the A/C. Remember that as the interior approaches the set temp, the Reatta A/C system controls the blower AND moderates the vent air temp to maintain the temp. In the very worst of summer I tend to just set the temp to MAX COOL and leave it as I really prefer the A/C to output its coldest air, regardless of the interior temp. The Reatta A/C is a subtle system. It is never in your face with massive amounts of frigid air. I have owned many auto-air systems and the Reatta is one of the most subdued I have encountered. That is not to say that it does a poor job but it is NOT going to produce icicles either.

Sorry, I did not catch that it included a reflective film. Pretty cool that it is self contained and uses GPS to determine speed and direction. Will be watching to see what you think. The price is certainly attractive. I would be open to adding this to my Reatta as I miss the C5's HUD every time I drive the Reatta.

My C5 vette has the factory HUD and I consider it a great safety advancement. I seldom glance down at the gauges as everything I need is right there on the windshield. As for aftermarket HUDs, they leave a LOT to be desired. Part of the GM HUD and all "proper" HUD systems is the area onto which it projects. While you can't see any difference in the windshield area there is an internal coating that reflects the image back such that even in direct sunlight it remains clear and bright. Also the angle between the reflecting surface and the projection plane needs to be proper. I too remember when the SSEi as well as the GP began to offer the HUD and it was clearly not part of the original design of the dash while the Corvette team while designing the C5 planned all along for the HUD and integrated it such that there was no bulge above the dash like on the Pontiacs.

This is what Ronnie and I have been discussing as to ship the sensor without damage. Great idea Dave! Also, here is a couple of shots showing the orientation that I have been describing

The sensor leads are actually quite robust. I don't see ANY need for a screen and besides there simply is NOT sufficient room for such without impeding the flow of the expanding refrigerant. As I mention, I am going to recommend that the sensor be oriented such that the sensor itself is inline rather than broadside to the refrigerant flow (the sensor alignment runs parallel with the external connector so it is easy to orient). This way the sensor leads will take the brunt of the refrigerant stream. I really don't think there would be any problems even oriented broadside to the stream but it is so easy to orient it to be inline that there is no reason to not do so.

Rotating the sensor in the refrigerant stream will not make any real difference in the registered temp but WILL reduce the mechanical load that the refrigerant stream places on the thermistor element itself. The small amount of difference that this thermistor will make could almost considered immaterial especially since it gives us an extra 1-2 degrees of cooling before the BCM will cycle the compressor off. I see no reason to trim the value as we are talking such a small offset and again it is in our favor when trying to optimize the cooling out of the evaporator

Based on what I know at this point, this thermistor will result in the evap temp actually swinging for more like -3 to around 8 which would be slightly colder on the average. If you use the BD028 method of optimizing the refrigerant charge you could either shoot for 2C (probably closer to .5-1C) or just a tad lower. The good news is that the BCM will report a temp about 1C higher than the actual temp in at the sensor using this thermistor, SO we potentially can gain an extra 1-2C lower evap temp before the BCM cuts out the compressor.

An update. Received the prospective thermistor and it soldered in nicely. It is MUCH smaller than the OEM disk thermistor and actually just marginally thinner than the support leads. Its width is virtually identical to the OEM disk so again a really nice fit. I determined earlier that the OEM thermistor was soldered in using good old fashioned tin/lead electronics quality solder (melting point between 230-250C). The thermistor under test was specifically designed to accept the same exact solder. There is a significant amount of solder connection on each end compared to the overall area of the thermistor, so it is mechanically secure between the leads. As the orientation of the thermistor inside the sensor can be set independent of the compression nut, I feel that it would be good to orient the thermistor in line vs across the flow of refrigerant to lessen the strain on the thermistor chip itself (ie the high speed flow of refrigerant in the line across the thermistor area...remember that the thermistor sits IN the stream of refrigerant) As I had posted earlier this thermistor is NOT an exact temp vs resistance fit to the OEM thermistor curve encoded in the BCM (thanks again to 2Seater for collecting the data) but what IS important is that it is VERY close at 0C which is the where we want the evaporator to run and therefore important that the BCM have a fairly accurate reading at that temp. Resistance of the thermistor installed in the sensor housing and immersed in a fairly large, stable ice water bath (distilled water and ice mixed) comes up with a resistance that the BCM would register as 1C. That is in our favor as that means that the BCM would allow the evaporator to pull a tad lower than -2 before cycling the compressor. At 17C (indoor ambient when I tested) the thermistor value would correspond to about 19-20C so again in line with what I saw at 0C. I also ran the numbers on the power dissipation when installed in the BCM circuit and we are looking at about 3 orders of magnitude between actual and max so self heating will NOT be an issue. Then I plugged it into the BCM harness and with my calibrated K-type thermocouple showing an ambient temp of 23.5C the BCM BD028 registered 27C which again is due to the curve of this thermistor not being an exact fit to the OEM curve in the BCM. Then, once again, I used an ice water bath and the BCM registered between 2-3 degrees. The fact that it did not indicate 1C as expected is likely due to my having to use small container of the ice water mixture due to space constraints and it likely was not stabilized as well as when I did the same test indoors. This rudimentary testing in the BCM circuit at least confirms that the thermistor is running in the same ballpark as expected. The next test will be to actually install and run it. My A/C system has been running fine for almost 4 years on R-134a with no leaks and at optimal charge as set by the BCM method, but I am considering purging the R134a and switching to R-152a as its heat properties are much close to R-12. I am currently involved in my transmission project, but I may make the switch to R-152a once that is complete and install the restored sensor for further testing. In the meantime, if anyone runs across either low or high A/C temp sensors on Riv/Reatta/Toro/Eldo/Caddy-in-general of our vintage, grab them regardless of condition as it is the housing that is going to be the commodity that can't be replaced as the salvage supply dwindles (mainly do to being crushed along with the cars). If pulling from salvage I recommend that you use a tubing cutter and remove a short piece of the refrigerant line with the sensor remaining installed in the cut away section so as to protect the internal sensor leads (got that idea from Ronnie) I am now confident that I have a workable restoration of the low temp sensor. FYI, I have 9 more of the thermistors on hand (more can be ordered) so I can do more if anyone is interested. Remember that this sensor stops our A/C unit dead in its tracks as it fails and the workaround for a failing sensor is at best temporary and there is NO workaround for a failed sensor!

Having recently replaced my Reatta's HB (failed due to backfire) and this being the 2nd one in the last few years (1st was to replace the factory install), I can state that the HBs sold for the 89 Reatta at Autozone do NOT have the 3 bolt holes for a puller but I had NO issues with pulling either off the crank once the bolt was removed (simply pulling with both hands was all it took). It was interesting the GM installed a splash guard on the "sedan" installation of the pre-series1 3800 but not on the Reatta. I found the OEM crank bolt as well as aftermarket replacement to be 24mm heads. I used that same method of sensor alignment as the guy detailed.

Bob, The OEM sensor is a bare thermistor disc soldered to two substantial leads sticking down into the refrigerant stream (the leads are substantial to provide mechanical robustness against the raging stream of refrigerant. Glass encapsulated thermistors would NOT be my first choice for a number of reason but mainly due to the lack of a good way to mechanically secure the thermistor (ie the thin wires going into the glass enclosure would be the weak link). There are other reasons why but that one alone makes it a non starter from my perspective. FYI, Mouser is a wholesale distributor to the electronics industry and as such represents a massive range of vendors. The vendor you located does have an SMD thermistor that would work as well, so I will keep them on file should I need another source. FYI, I really don't need to submit anything to them as their data sheets gives me everything I need to know.

Well, I thought I would drop an update on this matter. Ronnie shipped me his failed low temp sensor and I was able to determine that the failure mode WAS solder related, but unfortunately the stress from the solder failure actually pulled the soldering surface on the disc thermistor away and therefore the thermistor was destroyed. Bummer! FYI, by setting my soldering pencil at the minimum temp that would melt tin/lead but not silver solder I determine that good old fashioned, low melting point, tin/lead solder was used to attach the OEM thermistor between the sensor leads, so using such in a repair will not degrade the sensor longevity as we know that they lasted well over 25 years as designed and built. Silver solder has a much higher melting point and there is really no need for such plus subjecting thermistors to heat beyond their operating range does present the risk of a shift in their value. With the info that 2Seater gleaned from his trim pot vs BCM reported values, we knew the curve of the OEM thermistor. The bad news is that I have been TOTALLY unable to find an exact replacement. I then backed off a bit and thought about what we needed and decided to ditch fitting the curve and focus on the value at 0C which is where we WANT the BCM to hold the evaporator. I then went on a quest for any and all thermistors that would be close, regardless of packaging. Thanks to Mouser.com, I was able to narrow the search considerably. I finally found a SMD (surface mount device), NTC thermistor that came within 0.5C of the mark (ie at 0C actual, the BCM will report between 0C and 1C). The curve on this thermistor is a bit different so at 25C ambient, the BCM will report closer to 30C but that is immaterial as again, we are really only interested in a value at 0C. While this thermistor was originally designed to set on a PC board with flow soldered connections at each end, mounting it between the low temp sensor leads will be straightforward as its length is ideal to fit between those leads. Fortunately this was a part where units of 1 could be ordered (I found a closer fit, but the minimum order was 15,000!). I have ordered 10 of these little gems to test and I will report back once I have something to report.

I found the set at NAPA (ECHLIN v10067 / 2-18416) for under $5 for the set. These are the VITON type o-rings.

You mentioned that you planned to replace the outer CV boots. Not sure what they are getting for the CV boot replacement kits, but you might check out the cost of complete drive shaft replacements as they are really inexpensive (less that $50 ea at rock auto). I feel your pain on the list! It adds up, even over a fairly short period of time! Many of us on this forum as long since put more into their Reatta than the value of the car justifies, but I would venture as well that everyone would do it all over again knowing up front the costs that were going to be incurred.

With that cleared up, I can say that running synthetic oil will NOT harm the engine or its sensors. My Reatta 3800 has been on synthetic since DAY 1! If you are not getting the SES (service engine soon) light on the dash, then any codes that are setting are NOT drivability related (and some SES setting codes won't impact drivability to any great extent). When we discuss diagnostics, we ARE talking about the codes but it is up to YOU or your mechanic to sort out what to do. Based on the questions you have asked, I am assuming that you don't own a '90 Reatta/Riv Final Edition field service manual. GET ONE! You can't begin to maintain the Reatta without the FSM. Yes, this site is a wealth of information, but the site is not a substitute for looking up information in the FSM. The FSM is NOT a DIY guide but the troubleshooting and explanations that it contains are invaluable. In thinking back over conditions with symptoms even remotely similar to what you are describing, the only thing in my experience that was transmission related was a blown out vacuum modulator valve that was sucking transmission fluid out at just low enough rate to not cause smoke and once the fluid level got low enough, the downshift to 2nd gear on deceleration became VERY abrupt, but that is not really close to what you are describing. Regardless, I would check the vacuum modulator to ensure that it is working and will hold a vacuum properly. If you replaced it, understand that all the new ones have to be adjusted to find the sweet spot for the shift points (they come set in the middle of the their range). There is a small set screw in the end of the vacuum connection. All the way counterclockwise softens the shifts (more slippage) and all the way clockwise produces harder shifts (less slippage). On a high milage tranny, LESS slippage is preferable as you are typically on borrowed time anyway.

Most likely will NOT fix your problem as the TV cable only adjusts the shift points relative to the throttle position. You most likely have an engine control issue but it is too early to rule out a transmission issue entirely. Issues like you are experiencing typically require a process of elimination and that does NOT equate to throwing parts at it in hope of a quick fix, NOR does it mean blindly trying to adjust something.

First thing to know is that Dextron VI IS the correct fluid for ALL GM TRANSMISSIONS regardless of year of manufacture, PER GM! In fact, GM goes further and states that they no longer license the manufacture of ANY of the previous Dextron formulations as Dextron VI supersedes ALL previous formulations. So at this point, the ONLY formulation that has licensed and monitored specifics is Dextron VI (and by the way it IS pure synthetic). Not exactly sure what fluid the previous owner was running or what was used in the replacement. There are NO sensors per se in the transmission as it is a pure hydraulic controlled unit using nothing more than an internal mechanical pressure governor run off the output shaft, the throttle body valve (sets shift points relative to throttle position), the vacuum modulator (tweaks the shift points) and pressures in the valve body to control the position of several spool valves that in turn coordinate the two bands and 4 clutches (FYI, the 4 clutches are NOT the same as the 4 gears, but rather the 4 clutches and the two bands work together to produce the 4 forward gears and reverse). That said, running the WRONG fluid CAN mess with seals as well as the operation of the valve body. Ronnie already gave you the proper way to adjust the TV cable. It is NOT proper to attempt to adjust it to compensate for other problems. If you set it such that full throttle fully extends the TV cable, then that is where to leave it. FYI, the purpose of the TV cable is to progressively delay the shift point relative to engine RPM such that at wide open throttle, the transmission will almost require redline engine RPMs before it shifts (VERY HARD ON BOTH). FYI, while the Reatta has an excellent self diagnosis capability, there are MANY things for which NO codes are present. For instance the ICM (ignition control module) which is responsible for buffering the crack and cam sensors as well as controlling the spark timing has NO codes whatsoever. So don't be lulled into believing that no codes means all is well.