| Author | Message | ||
     Slowride |
I did about 400 miles the other day around DFW area on my Uly in a very very spirited manner. I ended up head back to the house via 121 and ended up in nasty stop and go traffic for over an hour barely moving in 85+ degree Texas weather. Outside of the heat on my legs which was nothing compared to my TLR v-twin I had, the Uly started clanking really bad. It almost sounded like a rod knocking it was so bad. Please keep in mind I wear ER6i headphones and could hear it through them. At one point I was going to shut down the bike, but decided to rev the back slowly, but steady all the way up to around 5 k and the noise started going away. I then spent another 20 min in traffic and it would start doing this again. I repeated the slow rev and it would go away. Oh yeah and it started idling erratic to boot. This didn't stop until I got it up about 40mph for about 5 miles and then stopped at a redlight. It was back to normal. This told me that maybe the engine was being starved for oil while at idle for so long and in stop n go traffic. The bike runs Syn3 oil and had just had its 10k service the day before with only 8K on the odo. When I finally reached home the fan was on full afterburners and the motor was ticking for almost 5 min. Anyone have any ideas? (Message edited by slowride on April 24, 2007) | ||
| Hughlysses |
Slowride, I'd guess you had a severe case of spark knock. Was the noise continuous, or just when you'd accelerate at/from low speed? If it was continuous, I'm wrong, but if it just occurred when you accelerated, it's almost certainly a spark knock. Revving the bike would increase the oil flow and could cool the pistons down enough (the underside of the pistons are cooled with oil jets) to temporarily cure the spark knock. If the engine actually does actually overheat, your check engine light will flash and the engine will go into a protection "skip spark" mode where (IIRC) the cylinders only fire every other stroke. This helps the engine cool down. If you haven't had a spark knock problem before, I'd guess the tech might have checked the timing and mis-adjusted it (advanced it too far) during your 10k service. Your engine was hot, but not "overheated", which would make the engine prone to knocking if the timing is advanced too far. | ||
| Slowride |
Interesting..... It knocked at idle as I never was able to get over 5mph for more than a 10-20 foot stretch. So it knocked the whole time once it started. When I reved it, I was at a stop and once I hit the 5k mark and let it idle down it stopped for about a minute and then started again. I will watch it this weekend as I plan to ride again in the emerging heat and if it happens again I will take it in to have the timing checked. I didn't even think about the timing advance. Dagone, shade tree mechanic roots of mine. | ||
| Lowflyer |
If it overheats, it is designed to throw an idiot light, shut down a cylinder, and run like sh%t. (Message edited by lowflyer on April 24, 2007) | ||
| Davo |
Slowride, I think you were hearing the valve train. Fortunately you had synthetic oil which means after the engine cooled back down after the hot period in traffic the oil was still oil and not sludge. I think the synthetic oil which is thin to begin with combined with an idling oil pump did not take up enough slack in the hydraulic lifters to keep the valve train quiet. It sounds like the Uly did very well not to hit skip spark. The stock right side scoop actually does a great job of cooling under the conditions that you described. I think you are in good shape, just keep telling yourself that noise is just vibration at an audible level. | ||
| Hughlysses |
I think the valve train noise theory makes sense. It might be worth checking your idle speed, though. I've had my tuber EXTREMELY hot idling in traffic before (using Mobil 1 V-Twin 20W-50 synth) and never got it hot enough to thin the oil out so much that the lifters wouldn't pump up fully. It may be that the tech set the idle too low on your Uly; Harley techs are notorious for setting the idle to ~900 RPM HD standard instead of the ~1100 RPM recommended for Buells. I'm thinking the combination of low idle speed and hot conditions might allow the oil pressure to drop far enough that the lifters wouldn't stay pumped up. | ||
| Slowride |
Thanks for the input, I am pretty versed in the Harley NOISY valve train. I owned several old Ironheads, the most recent an 83 bobber. The idle was a constant 1100rpm until this noise started and then it would go up and down like a car that had a bad air compressor. It would move between 1100 and 1500 until I rev'd it like I was describing earlier. I think I will run by the shop and get them to check the timing. Also, there was a thread on the xb board about guys running a 40wt oil, like a syn 15-40 or other combo and it greatly reducing the engine heat. Any creds to this theory. I am running Syn3 because it is still new in my eyes. I was running up to 50-60wt oil in my ironhead during the summer and it was great and the noise was very low. | ||
| Johnnylunchbox |
Slowride, the short period that I ran Shell rotella 5W40 synth in my XB12R I noticed the fan running less. This is hardly empirical evidence though. At idle in really slow moving traffic with little airflow I don't think the 40 or 50 weight will make a difference. I get serious pinging in my S3T when encountering conditions like you described. I've never gotten my XB to ping though, even in seriously hot conditions. (Message edited by johnnylunchbox on April 25, 2007) | ||
| Etennuly |
In summer conditions, when the temps are above 65F in the mornings I run HD 60 like the service manual recommends. It keeps that rattling V twin much quieter. | ||
| Whitj |
Mobil 1 15w50 Phoenix, AZ a warm 120 outside temp and no issue 12400 miles strong |
