So this article is about quite standard problem you can find on lots of cars, but here its about BMW. So you started getting first random lights on the dash and later it became permanent lights on mess on the dash. Usually you get ABS, DSC, DTC, BRAKE lights on and some messages on the idrive, like drive train malfunction, etc. Lots of mechanics diagnose it as bad abs sensors, abs pump etc, because it shows these errors on the scanner. YES, IT WILL NOT TELL YOU THAT ABS MODULE IS BAD, IT WILL ONLY TELL YOU WHAT SIGNALS ARE LOST, THEREFORE YOU END UP REPLACING LOTS OF WHEEL SENSORS, ABS PUMPS, SWITCHES AND SO ON. THE ANSWER IS INSIDE THE ABS UNIT-TINY GOLDEN WIRES BROKE OFF FROM AGE AND VIBRATION AND THAT'S WHY YOU GET ALL THOSE ERRORS! SO SIMPLY REPLACE ABS/DSC UNIT WITH A NEW ONE (600$+)OR GET IT REBUILD FOR 100-150$ WITH WARRANTY. NOTICE NEW CLEAN MODULE DOES NOT NEED CODING- IT IS SELF CODED, SIMPLY IT WILL WRITE VIN NUMBER AFTER YOU CONNECT IT FOR THE FIRST TIME, SO DON'T PAY ANYONE FOR "CODING" NEW UNIT. USED UNIT NEEDS TO BE REPROGRAMMED, BUT I RECOMMEND NEW UNIT OR REBUILD YOURS.
This article is about most common BMW cooling system faults and how to diagnose and repair it. Well, to start we need to know what perfect temperature specs for this V8 V12engine. When car is fully warmed up and idling for 10 minutes you should see these numbers: Upper Hose temperature-103-105C note: Lower hose should be within 60-70C, this is very important because it indicates proper cooling system function. Lower hose or coolant output readings should be within 60-70C with open tstat. very common mistake when mechanic thinks he bled the system right, but he doesn't know the heater control valve is clogged and there is no way to bleed the air out and lower hose stays COLD, even auxiliary water pump fails because of this. This screenshot shows proper transmission temperatures, when cooling system is fully functional and sealed: NOTE: Some cars have cold firmware which opens up thermostat earlier therefore engine running temps are lower. ALWAYS REPLACE RADIATOR CAP EVERY 5 YEARS, IT DOESNT LAST FOREVER! If temps stay at 105-110C, it definitively means you have an airlock, which causing overheating and lower hose running cold. This engine has self bleeding system, but it only works if cooling system is in great shape! So most common problem you cannot bleed the air out is HEATER CONTROL VALVE, which always goes bad after 5-7 years or even earlier. Its very easy to replace and costs around 140$. Usually rubber valves crack and deteriorate clogging the valve so you cannot bleed the air out, moreover it clogs heater core, which is a real pain to replace. So remove the valve and at least inspect it: -it should be clean inside and valves are open without 12V applied and easy to blow air through, in other words it should not have any restriction, but word of advice-REPLACE it, don't wait, and it will also improve heat cabin. LEAKS: -Front seal aka weep hole problem can be easily diagnosed checking weep hole on the timing cover Can be easily fixed with aftermarket solutions or with simple aluminum+RTV solution, which actually works pretty good. -Valley pan gasket leak. You need to remove intake to replace it. Be careful not to damage knock sensor which is very common. -Rear cover plate. Hardest point here-you need to remove transmission for that Other leaks include lower hose sensor leak and hoses also get old and is a good idea to replace them every 5 years. Also Vent hose connected to the heads near throttle body goes bad every 5years or 80-100kmls Always pressure test your cooling system- you cannot rely on visible findings saying there is no leaks. You cannot see 30% cooling hoses located in the rear of your engine. MAKE SURE YOU ALWAYS BLEED AIR OUT FROM COOLING SYSTEM EVERY TIME YOU WORKED ON IT: -FILL COOLANT TANK TO FULL WITH BMW COOLANT, LEAVE CAP OPEN. -TURN ON IGNITION (DONT START ENGINE YET) AND SET HEATER TO 90F WITH LOW FAN SPEED. MAKE SURE AUXILLARY PUMP IS RUNNING-YOU SHOULD HEAR IT ON THE DRIVER SIDE, LET IT RUN FOR 5 MINS -START THE ENGINE AND LET IT RUN FOR 5 MINS, CLOSE THE RADIATOR CAP -DRIVE YOUR CAR FOR AT LEAST 30 MINS -NEXT MORNING CHECK THE LEVEL, ADD COOLANT IF NEEDED Always take care of any leaks and check running temps! BMW cooling system is very important not only for the engine but for transmission as well- tranny cooler is connected to the same main radiator. Poor condition cooling system will ruin your engine and transmission very quickly. Running with airlock will eventually deteriorate all rubber gaskets including valve seals and stuck piston rings.
What you are supposed to know about your ZF6HP26, 6HP19, 6HP28 and similar ford Transmissions.BEST ADVICE FOR YOU: SINCE 99% issues with this trannies are related to valve body fluid pressure loss, I strongly recommend new (re manufactured) valve body from ZF (expensive 1600$), (you can find some companies offer this rebuild, but they charge almost new VB price, or rebuild it yourself with NEW SOLENOIDS PACK (300-400$) and SONNAX zip kit (150$). If after you rebuilt or replaced valve body and RESET ADAPTATIONS USING BMW SOFTWARE INPA OR ISTA IS A MUST, OR YOU WON'T SEE ANY DIFFERENCE AFTER REBUILT, BECAUSE TCM KNOWS VALVE BODY PRESSURE VALUES AND THEY MUST BE RESET. IF AFTER REBUILT, it's not shifting well, it means YOU WAITED TOO LONG WITH VALVE BODY REBUILT AND DESTROYED transmission hardware (bushings or actual clutches failed) and you need to rebuild it, but like i said main problem STARTS at valve body and then if not fixed in time you get worn out transmission. All those jolts, bumps or harsh shifts cause premature wear and tear on your tranny. Rule of the thumb is not to drive it if it jerks,or shifts wrong. replacing just solenoids without rebuilding valve body, where accumulators/pistons always go bad after 60-70k, will not get you perfect results, but might improve shifting quality. Remember-cheap people usually pay twice (no offense). So you hate the way tranny shifts and dealer and other shops didn’t find any faults and told youit is what it is and this is how it is intended to work! Well it is total lie they are trying to get rid of you with. In fact ZF 6HP26 6hp19, 6hp28 is a very good transmission, powerful, bullet proof pretty much if serviced in time and proper fluid pressure maintained! This tranny is still considered one of the best and has carbon clutches vs cheap paper ones you can find on Japanese cars. But this tranny has very serious and very important weak spots you have to take care of: -First thing first check tranny temperatures. If it is higher than 95C, then most likely you have a problem with tranny cooling system or your engine cooling has some leaks causing running it very hot. Usually high temps indicate following: 1) engine cooling system problem- air bauble or airlock 2) if everything is good with cooling system, check your tranny oil cooler- it gets clogged up pretty often and also indicates that some clutches or TC clutch is worn out and that debris clogged oil cooler. 3) worn out TC clutch slipping overheating transmission fluid. Your good engine temps are 103-105C and if it climbs to 107-110C in traffic, it means you’ve got a leak : -lower radiator hose sensor leaking (usually shows a white residue around the sensor) -valley pan under intake -rear cover plate between tranny and engine. Very common after 100k or 8-10yrs. -coolant tank cracked -radiator cap leaking pressure -coolant pipe seal leaking -other cooling issues It is very important to keep temps in specs not only because of few degrees, but because with leaking cooling system you lose coolant pressure introducing air in the system, causing uneven cooling and overheating both engine and tranny. Good OEM specs are 103-105 cycle when idling and lower hose should be hot around 60-80C. When you drive it tstat is controlled by ECU therefore it keeps it cool on the freeway. Easy way to test your cooling system 1) Disconnect aux pump connector assuming aux pump is working (they fail often) 2) Drive your car to warm engine well
- Turn on heater on hot but low speed
- check if you get hot air from vents for 10 minutes.
- If after a minute you noticed your heater is not hot anymore, it means you’ve got a leak!
- This Engine has self bleeding cooling system, which means you cannot get air pocket if system is well sealed.