Can this be removed?

[peerless]

Getting ready to install another rebuilt M42 and would like to replace and clean up the heater hoses. I believe this is a factory recall for the heater core blow-ups, but is it really needed? (Just found out this is a 'thermostat', do you really need a additional thermostat on the heater core?)

It just seems like a recipe for failure and leakage. If I eliminate it I could get rid of 6 points of potential failure and leakage.

Thanks in advance.

[ak96ss]

I don't believe mine ever had the recall done, and I haven't had a problem yet. FWIW. YMMV. It's your leg that will get scalded if it fails as described in the TSB...  

[peerless]

Do you have a link or specific information on this TSB.

I found out that their is a lower temperature radiator cap available as well.

From what I understand is the thermostat closes off the heater core if the temperature rises to a dangerous level. I would think with the lower temp cap and proper coolant system maintenance it should not be a problem removing this setup.

I do have new heater core hoses on the way and want to make a decision before I cut them up to keep this retrofit heater core saver.

Thanks,

[mkodama]

Sounds like it is a last minute fix to prevent BMW from getting sued.  I'm betting 99.9% of the time, that there will be no need for blocking off the coolant to the heater core when the temperature get real high.  

In that 0.1% chance though, if someone was driving their car around with the coolant temperature in the red, there is a chance a pipe failing and very hot water enters the cabin.  A much smaller chance, but more serious, is that hot coolant gets on the driver.

I guess BMW just decided to play it safe.

That's just my guess, but I would be interested to hear more about this.

[quinn11m20]

what year is your 318is? Because I have never seen that part. Thanx.

[peerless]

Well our theory's are correct. It is in fact due to coolant system neglect. The recall clearly states that any cooling system component can fail under overheating conditions. Just as in any car of any make or model. It just happens that in some cases the heater core control valve failed and due to its placement may have cuased a few unfortunate people to get burned.

But again, if you fail to maintain your car, your going to get burned. Its typical of todays litigious society. 'I didn't know I couldn't keep driving in the red and its your fault the cooling system blew up and burned me.' Same as 'I didn't know this coffee was scolding hot so I poured it on my pecker and got burned so I am suing you'.

Sounds like this damn heater thermostat gets the boot. I ordered the lower temp rad cap so if the system does get too hot, it will blow off pressure before blowing out the control valve.

You will notice that the control valve problem is listed as last in the list.

Recall ID#                         39233                          

Recall Reason                     VISIBILITY DEFROSTER/DEFOGGER SYSTEM:WINDSHIELD:HEATER CORE                                                                           Recall Date                     FEB 01, 1993                                                               Model Affected                     325                                                       Potential Units Affected                      375000                                                          

Recall Summary
 THE MALFUNCTION OR FAILURE OF A COOLANT SYSTEM COMPONENT RESULTS IN SIGNIFICANTLY INCREASED COOLANT TEMPERATURE AND A RESULTING INCREASE IN SYSTEM PRESSURE.

                                                                                                                             Consequence
 VEHICLES OPERATED UNDER THIS INCREASED COOLING SYSTEM PRESSURE CONDITION CAN SUFFER DAMAGE OR FAILURE OF PARTS OF THE COOLING SYSTEM SUCH AS (1) LEAKAGE FROM A COOLANT HOSE, (2) LEAKAGE OF THE RADIATOR OR EXPANSION TANK, (3) DISCONNECTION OF A HOSE FROM A PIPE OR A FITTING, AND (4)CRACKS IN THE HEATER CORE END PIECE RESULTING IN COOLANT LEAKAGE. IN SOME CASES, BOILING COOLANT CAN CONTACT THE LOWER RIGHT LEG OF THE DRIVER RESULTING IN BURNS. ALSO, ESCAPING COOLANT IN THE PASSENGER COMPARTMENT CAN CAUSE VAPOR FOGGING OF THE INTERIOR SURFACE OF THE WINDOWS, REDUCING DRIVER VISIBILITY.

                                                                                                                                  Remedy
 DEALERS WILL INSTALL A THERMOSTATIC BYPASS VALVE IN THE ENGINE COMPARTMENT TO CONTROL COOLANT TEMPERATURE IN THE HEATER CORE. ALSO, A NEW DESIGN RADIATOR CAP WILL BE INSTALLED, TO CONTROL PRESSURE AND PROVIDE GREATER COOLANT OVERFLOW IN THE EVENT OF OVERHEATING.

                                                                                                                                Notes
                         BAYERISCHE MOTOREN WERKE

[colin86325]

It's up to you.  A guy just posted on the E30 M3 SIG that his wife's ankle was scalded when they were tracking their car. A 20-year-old heater core was the culprit, and they didn't have the recall done.
I received a letter from BMW NA about 7 years(?) ago and they advised me (they tracked me down, as i was not the original owner) to have the car brought in for the free recall, but between not having a spare car and other reasons, I never had the work done.

I'd say check the hoses to preserve the state the car was in.  If the hoses are shot, then let the customer decide, with the risks known.  Is the heater core original?

[Cobra Jet]

Yep - discard that shit...  purchase new hoses @ the firewall from BMW (or your favorite online vendor).  All of the under intake BS on my 318ic was deleted by bmwpower when he rebuilt my M42 engine.  We discarded that "recall" POS too and installed new hoses.

I'd really like to know how many real world failures there were - and out of those failures how many were from neglect or lack of proper maintenance.  IMO, the BMW "recall fix" is very shoddy and just adds more possible failure & leakage points to the existing factory spaghetti hose mess under the intake...  



That sure was a clean cut for those hoses that were bridged in the above pic huh - you should have seen the butchered hoses we removed from my 318ic that also had the "recall fix" in place (you would think that being corrected at a BMW Dealer there would have been better craftsmanship - but it was a total butch job, worse than you see in your example).  

I have not read too many M42 threads online of heater cores just failing out of the blue and I don't see many folks even mentioning the M42 recall fix either.  Many BMW Enthusiasts beat the piss out of their rides - BUT also maintain them to the highest degree...  I think many folks (original owners) received the recall notice and just had the recall done due to not knowing any better OR thought it HAD to be done just because it was a recall sent out by BMW.  If the vehicle is being maintained properly or preventive maintenance is performed, I really don't think this recall is really necessary at all.

[peerless]

Fixed!

[mkodama]

Very clean and thorough job!  Looks much better!

How/what hose did you use to replace everything with?

[Cobra Jet]

peerless - Excellent!  Looks much better now, plus you reduce the number of possible failure junctions.

This is how mine is set up too, we went back to the original factory hoses & routing and ditched the recall parts.

mkodama - it's the factory BMW heater hoses.  That's how they looked and were routed to the engine when the car was built new (prior to the recall).

[batsbats]

Looks clean

[Slowered318]

I know this is an old thread but I have been doing some additional research, I'm in the process of removing even more of the "mess under my intake".

I'm not a cooling system expert so please correct me if this is bad advise. From what I have found BMW has two different radiator caps for the e30. For the m42 is #17111742231 2.0bar (30psi) and for the m20 is #17111742232 1.4bar (20psi). I would assume at upwards of 30psi a hose, gasket or heater core could rupture. It also doesn't make much sense that a bypass valve would prevent a rupture somewhere in the cabin if the entire system pressure is maxed out. I installed the 1.4bar radiator cap and no issues or coolant loss so far, also the hoses are just as plump when the engine is hot.

When I remove the bypass valve from the recall and install new "simplified" coolant hoses I thought it was a good idea to use the 1.4bar cap. I would rather have the pressure release at the radiator then inside my cabin or am I looking at this completely wrong? Given my entire cooling system is in good condition and filled to the correct level, I don't see any reason it would "boil over" if I were to reduce the maximum pressure?

I thought another option would be to build a brass "H" shaped fitting to go on the firewall. The coolant hose is roughly 3/4"and I'm sure a reduction (maybe 1/4") bypass can be installed with minimal effect to the heating system capacity. I think this would also help when bleeding air out and to regulate temperature throughout the engine.