Hi folks,
This is my first post - I'm new to the group. Glad to be a member of the "600 club"! I got my first 600 - a '72 sedan - way back in '73, I think it was, and kept it for several years. Loved that car, but it jumped timing chains twice in a period of a year or two. (I now realize that it was partly because I would sometimes drive the car too fast on the highway - over 80 mph! Red-line city! I know better now.) Bought my current 600 coupe from Mike O'Connor a year or so ago. Love it!
Two issues I'm dealing with:
1) I need to change fan and pulley bearings soon, and in the process I need to rethread the holes in the engine for the fan mounting. (Almost no threads left in the bolt holes!) I understand that Helicoils aren't the best solution, but was wondering what you guys have used. If you've used Helicoils, have they held up for you guys? Or do you strongly recommend against Helicoils?
2) Also, I have a buzz that shows up at anything above 4,000 rpm. It's been there ever since I bought the car. At first I thought it was the tach cable, but tried disconnecting the cable and the buzz was still there. I had wondered whether it might be engine ping, but I'm not inclined to think so because it really sounds more like a high-pitched buzz, like vibrating sheet metal or something, rather than the classic "marbles dropped on a steel plate" sound that is usually what pinging sounds like. Now I'm debating between loose sheet metal buzzing in the heat exchanger (or something else in the exhaust system) and something loose way up behind the dash. It's a bit difficult to localize the source of the sound. Does this kind of noise ring a bell with any of you guys? If so, and if you fixed it, what did the noise turn out to be? The thing's annoying enough that I try to keep the car down below 50 mph to avoid listening to it. I'd love to get rid of this noise!
Thanks guys - glad to be part of the group!
Richard McColman
Hillsborough, NC
new member - thread inserts & buzz
Re: new member - thread inserts & buzz
Richard, any luck with re-threading the holes for the fan shroud? Did helicoil work? I have two bolts that are broken off and I need to find a similar solution. I'm not having any luck removing the old broken bolts as they are broken off in the holes. Did you find the source of the buzzing sound? Mine turned out to be the fan shroud buzzing against the transmission housing near the bottom - because of the broken/missing bolts. The belt tensioner pulleys had bad bearings causing a lot of vibration in the fan and housing. I simply removed the fan belt and the engine sounds great. Can't run much without the fan though.
Henri
Henri
--- In
2cylinderhondas@yahoogroups.com
, "richmccolman" wrote:
> Hi folks,
> This is my first post - I'm new to the group. Glad to be a member of the "600 club"! I got my first 600 - a '72 sedan - way back in '73, I think it was, and kept it for several years. Loved that car, but it jumped timing chains twice in a period of a year or two. (I now realize that it was partly because I would sometimes drive the car too fast on the highway - over 80 mph! Red-line city! I know better now.) Bought my current 600 coupe from Mike O'Connor a year or so ago. Love it!
> Two issues I'm dealing with:
> 1) I need to change fan and pulley bearings soon, and in the process I need to rethread the holes in the engine for the fan mounting. (Almost no threads left in the bolt holes!) I understand that Helicoils aren't the best solution, but was wondering what you guys have used. If you've used Helicoils, have they held up for you guys? Or do you strongly recommend against Helicoils?
> 2) Also, I have a buzz that shows up at anything above 4,000 rpm. It's been there ever since I bought the car. At first I thought it was the tach cable, but tried disconnecting the cable and the buzz was still there. I had wondered whether it might be engine ping, but I'm not inclined to think so because it really sounds more like a high-pitched buzz, like vibrating sheet metal or something, rather than the classic "marbles dropped on a steel plate" sound that is usually what pinging sounds like. Now I'm debating between loose sheet metal buzzing in the heat exchanger (or something else in the exhaust system) and something loose way up behind the dash. It's a bit difficult to localize the source of the sound. Does this kind of noise ring a bell with any of you guys? If so, and if you fixed it, what did the noise turn out to be? The thing's annoying enough that I try to keep the car down below 50 mph to avoid listening to it. I'd love to get rid of this noise!
> Thanks guys - glad to be part of the group!
> Richard McColman
> Hillsborough, NC
Re: new member - thread inserts & buzz
Someone had drilled mine out for 8m and than managed to wreck those threads. I drill that out to 10m and made (4) inserts from pieces of 10m bolts drilled and tapped for 6m bolts. I used loctite on the 10m inserts and anti seize on the 6m threads. I snugged the inserts in as you would a stud using a longer 6m screw and a nut.
On removal of broken screws, I have had luck with drilling and using a tiny easyout.
On removal of broken screws, I have had luck with drilling and using a tiny easyout.
--- In
2cylinderhondas@yahoogroups.com
, "hfmtn600" wrote:
> Richard, any luck with re-threading the holes for the fan shroud? Did helicoil work? I have two bolts that are broken off and I need to find a similar solution. I'm not having any luck removing the old broken bolts as they are broken off in the holes. Did you find the source of the buzzing sound? Mine turned out to be the fan shroud buzzing against the transmission housing near the bottom - because of the broken/missing bolts. The belt tensioner pulleys had bad bearings causing a lot of vibration in the fan and housing. I simply removed the fan belt and the engine sounds great. Can't run much without the fan though.
> Henri
> --- In
2cylinderhondas@yahoogroups.com
, "richmccolman" wrote:
> > Hi folks,
> > This is my first post - I'm new to the group. Glad to be a member of the "600 club"! I got my first 600 - a '72 sedan - way back in '73, I think it was, and kept it for several years. Loved that car, but it jumped timing chains twice in a period of a year or two. (I now realize that it was partly because I would sometimes drive the car too fast on the highway - over 80 mph! Red-line city! I know better now.) Bought my current 600 coupe from Mike O'Connor a year or so ago. Love it!
> > Two issues I'm dealing with:
> > 1) I need to change fan and pulley bearings soon, and in the process I need to rethread the holes in the engine for the fan mounting. (Almost no threads left in the bolt holes!) I understand that Helicoils aren't the best solution, but was wondering what you guys have used. If you've used Helicoils, have they held up for you guys? Or do you strongly recommend against Helicoils?
> > 2) Also, I have a buzz that shows up at anything above 4,000 rpm. It's been there ever since I bought the car. At first I thought it was the tach cable, but tried disconnecting the cable and the buzz was still there. I had wondered whether it might be engine ping, but I'm not inclined to think so because it really sounds more like a high-pitched buzz, like vibrating sheet metal or something, rather than the classic "marbles dropped on a steel plate" sound that is usually what pinging sounds like. Now I'm debating between loose sheet metal buzzing in the heat exchanger (or something else in the exhaust system) and something loose way up behind the dash. It's a bit difficult to localize the source of the sound. Does this kind of noise ring a bell with any of you guys? If so, and if you fixed it, what did the noise turn out to be? The thing's annoying enough that I try to keep the car down below 50 mph to avoid listening to it. I'd love to get rid of this noise!
> > Thanks guys - glad to be part of the group!
> > Richard McColman
> > Hillsborough, NC
-
richmccolman
- Posts: 39
- Joined: Wed Jun 20, 2012 9:47 am
Re: new member - thread inserts & buzz
Hi Henri,
Yes, I had at least some success with rethreading. Actually, it turned out that two of the four bolt holes for mounting the fan shroud were fine -- threads were intact, even though only one of those two had a bolt in it. I think I just had to chase one of those two holes with a tap. Of the two fan shroud bolt holes with problems, one simply had worn out threads -- I was able to drill (using a right-angle drill attachment, since there's not much depth with the engine is the car), tap, and helicoil that one. The other one was a different story. It had part of an old bolt broken off in it. I tried drilling it so as to use a screw extractor, but couldn't get a good bore of any depth. (Probably similar to your experience.) I finally gave up and took a different approach to that one. It's a complicated procedure, and one that I wouldn't necessarily recommend, but it kinda worked -- that is, as long as I don't torque that one bolt very much. (I figure it's not a huge issue, now that the other three are in great shape now.)
As to my buzzing noise, I did check to see if the noise was related to the loose fan shroud, but once I got the bolts and mountings fixed, the buzz was still there. I replaced the fan and belt pulley bearings also, thinking those could be making the noise, but as I said, I still have the buzz. A check I did with an automotive stethoscope indicates that the buzz is likely coming from inside my heat exchanger, as Miles suggested might be the case.
Regarding your removal of the fan belt, it's my understanding that you can go without it entirely -- as long as you keep the car moving forward! ;-) Hard to do when driving in town, I know.
So I suppose I've not been of much help to you.
BTW, it's a very common occurrence for 6mm bolts to get over-torqued, which I suppose is why so many engines have problems with these smaller bolts getting broken, including for the fan shroud. (Similar thing happens A LOT with the oil screen plate mounting studs on old air-cooled VW engines). Too many people don't know how to step down their torque technique for the smaller bolts. (I suffered from this over-torquing syndrome in my early days, too.) In reality, these small bolts need only about the same amount of torque as can be applied using a screwdriver -- 3-6 ft/lbs. Best thing to do when tightening 6mm bolts is to torque the ratchet using a one-handed technique -- putting the hand around center of ratchet rotation, NOT out on the ratchet handle.
Best of luck getting your fan shroud bolt holes, etc, fixed!
Richard
Yes, I had at least some success with rethreading. Actually, it turned out that two of the four bolt holes for mounting the fan shroud were fine -- threads were intact, even though only one of those two had a bolt in it. I think I just had to chase one of those two holes with a tap. Of the two fan shroud bolt holes with problems, one simply had worn out threads -- I was able to drill (using a right-angle drill attachment, since there's not much depth with the engine is the car), tap, and helicoil that one. The other one was a different story. It had part of an old bolt broken off in it. I tried drilling it so as to use a screw extractor, but couldn't get a good bore of any depth. (Probably similar to your experience.) I finally gave up and took a different approach to that one. It's a complicated procedure, and one that I wouldn't necessarily recommend, but it kinda worked -- that is, as long as I don't torque that one bolt very much. (I figure it's not a huge issue, now that the other three are in great shape now.)
As to my buzzing noise, I did check to see if the noise was related to the loose fan shroud, but once I got the bolts and mountings fixed, the buzz was still there. I replaced the fan and belt pulley bearings also, thinking those could be making the noise, but as I said, I still have the buzz. A check I did with an automotive stethoscope indicates that the buzz is likely coming from inside my heat exchanger, as Miles suggested might be the case.
Regarding your removal of the fan belt, it's my understanding that you can go without it entirely -- as long as you keep the car moving forward! ;-) Hard to do when driving in town, I know.
So I suppose I've not been of much help to you.
BTW, it's a very common occurrence for 6mm bolts to get over-torqued, which I suppose is why so many engines have problems with these smaller bolts getting broken, including for the fan shroud. (Similar thing happens A LOT with the oil screen plate mounting studs on old air-cooled VW engines). Too many people don't know how to step down their torque technique for the smaller bolts. (I suffered from this over-torquing syndrome in my early days, too.) In reality, these small bolts need only about the same amount of torque as can be applied using a screwdriver -- 3-6 ft/lbs. Best thing to do when tightening 6mm bolts is to torque the ratchet using a one-handed technique -- putting the hand around center of ratchet rotation, NOT out on the ratchet handle.
Best of luck getting your fan shroud bolt holes, etc, fixed!
Richard
--- In
2cylinderhondas@yahoogroups.com
, "hfmtn600" wrote:
> Richard, any luck with re-threading the holes for the fan shroud? Did helicoil work? I have two bolts that are broken off and I need to find a similar solution. I'm not having any luck removing the old broken bolts as they are broken off in the holes. Did you find the source of the buzzing sound? Mine turned out to be the fan shroud buzzing against the transmission housing near the bottom - because of the broken/missing bolts. The belt tensioner pulleys had bad bearings causing a lot of vibration in the fan and housing. I simply removed the fan belt and the engine sounds great. Can't run much without the fan though.
> Henri
> --- In
2cylinderhondas@yahoogroups.com
, "richmccolman" wrote:
> > Hi folks,
> > This is my first post - I'm new to the group. Glad to be a member of the "600 club"! I got my first 600 - a '72 sedan - way back in '73, I think it was, and kept it for several years. Loved that car, but it jumped timing chains twice in a period of a year or two. (I now realize that it was partly because I would sometimes drive the car too fast on the highway - over 80 mph! Red-line city! I know better now.) Bought my current 600 coupe from Mike O'Connor a year or so ago. Love it!
> > Two issues I'm dealing with:
> > 1) I need to change fan and pulley bearings soon, and in the process I need to rethread the holes in the engine for the fan mounting. (Almost no threads left in the bolt holes!) I understand that Helicoils aren't the best solution, but was wondering what you guys have used. If you've used Helicoils, have they held up for you guys? Or do you strongly recommend against Helicoils?
> > 2) Also, I have a buzz that shows up at anything above 4,000 rpm. It's been there ever since I bought the car. At first I thought it was the tach cable, but tried disconnecting the cable and the buzz was still there. I had wondered whether it might be engine ping, but I'm not inclined to think so because it really sounds more like a high-pitched buzz, like vibrating sheet metal or something, rather than the classic "marbles dropped on a steel plate" sound that is usually what pinging sounds like. Now I'm debating between loose sheet metal buzzing in the heat exchanger (or something else in the exhaust system) and something loose way up behind the dash. It's a bit difficult to localize the source of the sound. Does this kind of noise ring a bell with any of you guys? If so, and if you fixed it, what did the noise turn out to be? The thing's annoying enough that I try to keep the car down below 50 mph to avoid listening to it. I'd love to get rid of this noise!
> > Thanks guys - glad to be part of the group!
> > Richard McColman
> > Hillsborough, NC