other Gas Tank Heat Shield. Does Your Car Have One?

[PaulTWinterton]

The "protection plate" ( heat shield) , or lack of, was brought to my attention in a previous thread where I was complaining of a whining electric fuel pump.  The consensus was cavitation, possibly caused by overheated fuel, after a prolonged freeway run.  The rear muffler is very close to the gas tank and could potentially cause "boiling" of the fuel in the tank, if no heat shield is in place.

 

My 73 never had one.   I'm 99.9% sure.

 

It appears that beginning in late 1973 2002 models  came with a "protection plate".  Not before?   Anyone have one on an earlier car?

 

 

Edited May 10, 2015 by PaulTWinterton

[Conserv]

I kinda thought it was a square taillight thing (to have the heat shield). But I've never actually "examined the issue"!

Regards,

Steve

[tashakes]

FWIW my 76 has it.

[DRedman]

my parts book has a notation under pn 16 11 1 114 997 with "model 75".  The mounting plugs (2ea) are pn 32 21 2 675 171 So I assume 1975-1976 had them?

[peterschop]

My June of 74 does not have it. But was the tank ever out? Can't tell ya.

Edited May 10, 2015 by peterschop

[M3M3]

I doubt the lack of that part has anything to do with your issue.

[jgerock]

I doubt the lack of that part has anything to do with your issue.

Agree with Marshall. My bet is that BMW added the heat shield beginning in 1975 due to the reactor on the exhaust manifold. Same cars could also have a heat shield for the center support bearing.

Edited May 10, 2015 by jgerock

[PaulTWinterton]

I'm thinking that the engineers at BMW must have had reasons for adding the (2) heat shields. Reactor? Is that a emissions thing? Obviously they didn't see a need for them in the previous models. CSB shield makes sense.

I thought vaporization of the fuel causing my whining pump was a long shot but it made me curious about the heat shield.

By the way...my pump has not whined since my post. Only the one time. Looked for clues, fittings, filters, looseness...found nothing. I'll carry the original (working) pump with me, just in case.

[John_in_VA]

I'm thinking that the engineers at BMW must have had reasons for adding the (2) heat shields. Reactor? Is that a emissions thing?

Yes.

[OriginalOwner]

my '74tii has no heat shield.

 

the '75 Green Loaner does have a heat shield.

 

Cheers,

 

Carl

[M3M3]

Reactor? Is that a emissions thing?

 

yes. 

[rstclark]

The correlation of the heat shield to the Thermal Reactor makes a lot of sense.  The thermal reactors in an over rich fuel setting could glow red hot Even when they didn't glow the could send more heat down the exhaust system.  The heat shield was most likely there as a precaution for the thermal reactor and the chance that it could generate very high tempretures 

[Conserv]

my '74tii has no heat shield.

the '75 Green Loaner does have a heat shield.

Cheers,

Carl

Even 49-state '76 models -- which have no reactor -- have the heat shield. Any possibility the heat shield's implementation coincided with the change from right-rear exhaust exit to center-rear exhaust exit? Could shortening the exhaust run somehow have increased the exhaust temperatures next to the tank?

Regards,

Steve

[roadhog0]

My 76 has a gas tank heat shield, the Tii, I dont know, I'll look later

[thinksound_mike]

my 74 does not. no idea if it had one at some point. it did have the thermal reactor and all that; but not anymore!