engine and drivetrain What is clearance between radiator and cooling fan?

[DakarDoug]

Here we go, let me give you some background. About 10 years ao, my cooling fan took out my radiator on a trip. Can't recall if I hit a bump which caused the engine to dive into the radiator or what exactly happened. I was able to get a replacement 320i radiator which didn't fit well so what I wound up doing was taking off the red cooling fan and then mounting an electric fan in front of the radiator. This worked ok for a number of years but the second electric fan has now crapped out again and I don't want to shell out the bucks for a replacement. So what I did was try to turn it back to stock (after all, these German engineers are much smarter than I am) by reinstalling the red cooling fan and a replacement 2002 radiator. The problem is that the radiator does not fit properly. With the radiator in place, it rubs against the cooling fan. I know I have installed everything correctly. Is it even possible that my engine is sitting too far forward or was there maybe some front end damage causing this that isn't visible? This is really driving me crazy and need some help. Thanks.[/i]

[Napes]

The clearance between the fan and raditor should be around 1/4" to 3/8". It's possible that the right hand engine mount stop was not properly adjusted at some point and the engine has slid forward under braking. Check the Haynes Manual (p.45 and Fig. 1.27 in the 1987 edition) for the correct adjustment, or check the BMW Repair Manual for the same thing.

Bob Napier

[TobyB]

Try sliding your differential back.

Seriously.

The whole drivetrain's position is dependant on where the diff is.

This was one of those places where they maybe should have left a bit more room.

Very much unlike the E36 318....

t

[c.d.iesel]

a FAT pinky

or a skinny index finger

[oldguy]

Whatever the clearance is, it will be less at 7000 rpm. error on the fat side or find fan marks in your radiator.

[Koblenz]

I had this problem. My car was missing the engine mount stop. Its a metal piece that fits under the passenger side mount. No problem since then.

[c.d.iesel]

and while you have yer flashlight lit,

look at the drivers side nount - the arm that

the mount is attached to next to the steering

gearbox - look for cracks or a break in the arm

if both mounts are 20+ years old?

REPLACE them today. Easy and cheap!

(trans mount also)

[Kpeters]

Having the same problem thanks for all the great info.

[DakarDoug]

Thanks for the ideas. Motor mounts look good. Motor mount stop is in place and adjusted properly. Sub-frame is not cracked. Will continue to look around. I think this weekend I will try moving the engine and differential back as far as it will go and see if that gives me the needed clearance. If not, she's going to the shop and I will let a trained mechanic figure it out.

[Guest_anonymous]

Wash in cold water on delicate cycle, tumble dry no heat.

This last engine I put in has more radiator clearance than the last three had ?

Dunno! I've read it referred to as shortened engine bay syndrome. But the only cure alluded to seems to be buy more cars.

[JerryC]

That story sounds somewhat like mine. My tii came to me with an electric fan that was not up to the job. It used a manually switched fan to try to cool the engine, with marginal performance. The car nearly overheated in a traffic jam with a slight tail wind.

So, I decided to install the factory fan. It ended up being way too far forward; the radiator would not go back in. In poking around, I discovered the rubber transmission mount was broken. This happened because the 5-speed conversion cross member was too far back. That happened because the driveshaft was 200mm too long, even with the differential as far back as possible! Once the driveshaft was shortened to the proper length for a 5-speed conversion and the rear crossmember was located to its proper position, there was about 1/2" clearance between the fan and the radiator. I can only guess how many trips under the car in between phone calls with Jeff Ireland and Rob Torres it took to figure all this out. It sucked.

So, the lesson is, if you're looking to buy an '02 a 5-speed swap, check the work carefully!

[DakarDoug]

Aha! I think you guys are on to something. My car has a 5 speed so am wondering if everything was done correctly. I hate to say it but I did the conversion myself about 10 years ago so it probably wasn't done correctly. I guess I need to start at the differential and move that all the way back and then readjust everything else. Sound about right?

[dbmw2002]

Kinda new to the diff discussion, not new to a fan eatin my radiator, so you crawl underneath and loosen the diff mounts, and how does it move if motor and trans are bolted down? Give me the qwik 3 step on this one, thought I was goin fishin this weekend.

[TurboDogsDad]

Odd, I just got a new red fan for MacZooZ after discovering the ends of the fan chewed off. It looks to me like the new fan will hit the upper tank of the rad unless I shift things around. Guess I have my list of stuff to check, though I'm with Dave (previous post), moving "just the diff" won't buy anything, correct? That will just leave room to move the rest of the drivetrain back?

[FB73tii]

Interesting discussion. I have only moved the diff in cases where the guibo was distorted and moving the diff relieved tension on it. I can see how perhaps old (squishy) stock rubber motor mounts would allow the engine to move back a bit if pulled by the diif, but then there is for/aft loading on the drivetrain which is likely not good for the guibo or thrust loads. Unless the diff was too far forward and was actually pushing the engine forward. In this case I think you would see some guibo distortion as evidence.

 

With poly engine and trans mounts It seems to me the engine just sits where it is, with or course a little diagonal adjustment via placement of the driver side motor mount.

 

the driveshaft was 200mm too long

 

Wow, must have taken quite a large shoe-horn to get that driveshaft in! Or did you mean 2mm?

 

--Fred '69 4-spd & '74tii 5-spd