Engine knock after its take operating temp with slight load at 1500 /2000 rpm

Tkperera · February 25, 2020

Its suzuki swift hT51S 2005 m13a engine

Engine knock comes with light load like ac on status, between 1500 to 2000 rpm after the engine gets its operating temp. all sensors checkd, ecu changed, no eny DTC, no burning oil. No smoke.. spark plug change ifr6j11. What happen ? How will fix that knok. ? Please help.

Hyaenidae · February 25, 2020

A video would help

Did you try the easiest remedy, pumping some 95 octane from a different filling station?

Edited February 25, 2020 by Hyaenidae

Tkperera · February 25, 2020

Yes i did it before filling 95 octain but still same.

Edited February 25, 2020 by Tkperera
Change spcific number

Tkperera · February 25, 2020

On 2/25/2020 at 3:55 AM, Hyaenidae said:

A video would help

Did you try the easiest remedy, pumping some 95 octane from a different filling station?

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Yes i did it before filling 95 octain but still same.

iRage · February 25, 2020

and you are sure it is a pre-ignition sort of knock ?

what is the oil you use ?

is it just when you have a load in the car ? or does it come up even if you leave the car idling for a while (letting the engine heat up to op temp) and then reving to 1500-2000 ?

AVANTE · February 25, 2020

Your symptoms do sound the same as failing crankshaft bearings. Once it comes to operating temp, there will be a metallic knocking sound/rattle after 2000rpm. Can't say anything for sure without a check in the garage, which I suggest you do as quick as possible to prevent further damage.

gayanath · February 25, 2020

1. Millage?

2. Previous engine related repairs (inducing cleaning)?

3. How long is this fault?

4. Is this coming with acceleration?

5. Is this coming with deceleration?

6. Is this coming with continuous same speed about 70 km/h?

7. Did you check it at expressway? high speeds?

8. No sound with load? (with 4 people and slight acceleration)

Tkperera · February 27, 2020

On 2/25/2020 at 5:42 AM, iRage said:

and you are sure it is a pre-ignition sort of knock ?

what is the oil you use ?

is it just when you have a load in the car ? or does it come up even if you leave the car idling for a while (letting the engine heat up to op temp) and then reving to 1500-2000 ?

Expand

Mobil 15-40 its come with load between 1500-2000. It does not come up when ists idleing and rev in nutral

iRage · February 27, 2020

Okay....so that leaves that out...however...when the car is idling and you rev it..it does come up ?

Next issue could be the crank bearings...by the way...I suppose you do not see any significant loss in oil..but if you could take a look at the bottom of the engine see if you can spot any oil seepage from either end...

Tkperera · February 27, 2020

On 2/25/2020 at 8:49 AM, gayanath said:

1. Millage?

2. Previous engine related repairs (inducing cleaning)?

3. How long is this fault?

4. Is this coming with acceleration?

5. Is this coming with deceleration?

6. Is this coming with continuous same speed about 70 km/h?

7. Did you check it at expressway? high speeds?

8. No sound with load? (with 4 people and slight acceleration)

Expand

1. 166000 km

2. I dont know abt previous owners,

I did efi tuning , chanege knock sensor , iat sensor , ect sensor , oxygen sensor , tp sensor with new throttle body , map sensor , and finally change ecu

3. Since i own this car.

4. Its fade away when accselarating

5. Its fade away when deaccselarating

Only come with low rpm range with slight load

6 . With high rpm more than 2200 not came.

8 . Yes its comes with load just before down shift when i accselarate to drive uphill

Tkperera · February 27, 2020

On 2/27/2020 at 4:26 AM, iRage said:

Okay....so that leaves that out...however...when the car is idling and you rev it..it does come up ?

Next issue could be the crank bearings...by the way...I suppose you do not see any significant loss in oil..but if you could take a look at the bottom of the engine see if you can spot any oil seepage from either end...

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No it does not come when engine rev at P or N position . There are no significant oil loss, no oil leak under the engine, and this car has best gas milage 18kmpl.

Tkperera · February 27, 2020

On 2/25/2020 at 5:42 AM, iRage said:

and you are sure it is a pre-ignition sort of knock ?

what is the oil you use ?

is it just when you have a load in the car ? or does it come up even if you leave the car idling for a while (letting the engine heat up to op temp) and then reving to 1500-2000 ?

Expand

iRage · February 27, 2020

On 2/27/2020 at 4:42 AM, Tkperera said:

No it does not come when engine rev at P or N position . There are no significant oil loss, no oil leak under the engine, and this car has best gas milage 18kmpl.

Expand

No..not an oil leak..an oil seepage..like when you look at the lower end do you see slight dampness and gunk built over....

Tkperera · February 27, 2020

Yes sure it must be pre ignition. coz its completely stop when i detached the IAT sensor clip.

Tkperera · February 27, 2020

On 2/27/2020 at 4:47 AM, iRage said:

No..not an oil leak..an oil seepage..like when you look at the lower end do you see slight dampness and gunk built over....

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Ah yes , little bit dampness in crank position sensor . The micanic says crank sensor O ring is leak.

invisibleuser · February 27, 2020

I would like to share my experience as well even-though its not the same model. Mine is Toyota Vios 2004, 160,000 km and I'm also experiencing the same. Doesn't matter whether there is a load or not, at low rpms engine knock is there. Specially when gears are changing from 1to 2nd and 2nd to 3rd (Auto transmission). Engine tune up, change of plugs has been done but not luck so far.

Edited February 27, 2020 by invisibleuser

gayanath · February 28, 2020

On 2/27/2020 at 4:35 AM, Tkperera said:

1. 166000 km

2. I dont know abt previous owners,

I did efi tuning , chanege knock sensor , iat sensor , ect sensor , oxygen sensor , tp sensor with new throttle body , map sensor , and finally change ecu

3. Since i own this car.

4. Its fade away when accselarating

5. Its fade away when deaccselarating

Only come with low rpm range with slight load

6 . With high rpm more than 2200 not came.

8 . Yes its comes with load just before down shift when i accselarate to drive uphill

Expand

@iRage, Couldn't this issue be associated with VVTi system (may be some kind of issue in actuator, tensioner, or something) ?.

Guess that, some component working for some range but not functioning properly for another range...

Harshitha · March 5, 2020

On 2/25/2020 at 3:49 AM, Tkperera said:

Its suzuki swift hT51S 2005 m13a engine

Engine knock comes with light load like ac on status, between 1500 to 2000 rpm after the engine gets its operating temp. all sensors checkd, ecu changed, no eny DTC, no burning oil. No smoke.. spark plug change ifr6j11. What happen ? How will fix that knok. ? Please help.

Expand

I have the same model and experiencing the same problem. As far as I inspected various aspects of statistics of the vehicle when operating, I do not really see any error. However, something is wrong somewhere and I believe we connect together and sort this out as it is a huge issue to coop with.

Harshitha · March 11, 2020

Here is the good news! After being tracking each and every data ECM produces while driving and knocking, it was realized that there is nothing to do with any sensors or anything related to false data. Purely it was a dead end by the way.

so it was convinced that this is something related to combustion chamber or exhaust back pressure. Since pulling the exhaust header out is the easier way, I decided to go ahead with it.

After removing the header, I realized that one catalytic converter honeycomb was entirely missing and other one is still in tact. I believe there should be two cat converters by the way! In this model, there are two exhaust header chambers (bank 1 and bank 2) with two separate o2 sensors in place and no o2 sensors in place after the cat converters. Each chamber/bank has each cat converter in place.

My expectation was a clogged cat but one is already missing and other one was not so clogged, it was a dead end again to me. But when I was trying to clean the cat with soapy water, I realized it took so long to travel water to the other side. I submerged it for few hours and cleaned thouraly and dried it under hot sun.

while the cat dries, I inspected the exhaust ports and found out leaking oil from top of the valve may be due to leaky valve seals (hoping). This could be same in intake side I assume. Since this requires tons of work and head needs to come out, I kept it for future repair.

after drying out I fixed the header and also cleaned both o2 sensors just in case if there are any clogged passages that may not visible to bare eye.

today I drove the car as usual to office and had few mid day trips around Colombo and did all the possible steps to create the knock but it was hardly there!

So I assume that there was an exhaust back pressure that was causing the engine to knock. Or may be cleaned o2 sensors did the trick? I don’t think so as I get the same reading from sensors like before.

opened for discussion.