Discussion in 'Engine Compartment' started by drapkarthik, Jul 14, 2012.
Yeah. Timing chain replaced 20K kms ago. Car has done 82K
Quite interestingly I had also faced lots of starting problems for about a month or so before my punto' s chain snapped. since the battery was also 3+ yrs old I used to suspect the battery.
So starting trouble looks like a very valid symptom of Timing chain trouble to me.
Read here ,clearly mentioned about the starting trouble due to Timing chain problem.
I see that some people are doubting FIAT of playing foul in changing the timing chain on just 90hp engines and not 75 hp engines.
1. The 90 hp generates more power.
2. The 75 hp generates full torque at lower rpm than 90 hp and 90hp owners tend to race more.
3. Linea is heavy than punto (exclude punto 90hp)
4. Fiat has seen most of the cases of failure in linea - so they changed the schedule only on 90 hp engines.
5. Fiat had involved the timing chain supplier and also the italian folks. The test bed engine dint face any timing chain failures at all.
6. Chain supplier has an argument that why cars only in india have timing chain failures and not the ones sold all over the world.
7. They are still in a process of finding the exact cause , replication of which seems quite diff.
With all the above i suspect the continuous strain on the underpowered engine driven in city traffic causes this issue. We tend to pull the car more in 1st and 2nd gear to extract power which makes the engine to drive more in peak load while the other engines like 1.5 etc with same bhp run under less stress.
Great points, but I have a slightly different perspective. 90 Bhp engine having a VGT, guess it generates more Boost. The timing chain which drives the cam shaft now needs more power during compression stroke to close the intake valve and also to keep the intake and exhaust valves closed during the power stroke. All the stress is on the timing Chain of 90 BHP engine to over come these increased forces when compared to the 75 BHP engine. And again, I guess we rev a lot to get drivability in the Linea, the timing chain simply need to run more revolutions as we rev more. The Apt way for measuring the life of the timing chain should have been based on the number of revolutions of the timing chain and not based on number of Kms the car has run.
Practically, the timing chain does more cycles for covering 60k kms for a city car as it does 2k rpm in 1st and 2nd gear and reaches sub 40 kmph speed than for a car which does 2k rpm in 5 th gear and 80 kmph. In this comparison, the city car's engine would have done twice the number of cycles than the highway car and so does the timing chain. So as rightly pointed out, those who rev the car too much or does too much city driving are in a soup.
Btw,Do we have such bumper to bumper super crawl traffic in other countries where Linea is sold ? If its a no and they do only highway rides, then Timing Chain in India is destined to fail early because we are so stuck up in traffic all the time.
what shud be the ideal time for chain replacement in 75bhp motor?
Out of 100% if your Drive is 75% in City and 25% Highway then change it in between 60K and 70K Kms.
if its purely 75% on Highway and 25% City then.... dont know(Let me fail , i have crossed 1Lakh without timing chain change)
I have started getting this metallic noise when I start the engine. Can someone please comment? Vijay Khasa attributes this to the timing chain while my dad attributes this to the starter.
Yes I would at best guess it to starter too. There is self at just about 4th sec .. what's that first 3 sec noise.
But one thing for sure this needs a thorough look see by a professional.
Thats some ambient noise from the surroundings I guess. I will look into that hammering noise again tomorrow that can be heard in the first 3 seconds. The culprit noise is heard after the engine is started.
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