Engine Shaking & low power - 2000 s70 FWD Base Model

[rtjl]

Some updates.

After a 10min drive warm up (oil between 60-70% of meter), I attempted some tests.

0. The car does not drive above 20-30km/h. There is very little power.

1. First, I attempted the glove test. It was not inflating, nor was it being sucked in. It seemed to be alternating (inhaling & exhaling), but if so only very slightly.

2. One by one I unplugged the Ignition pencils.

Surprisingly, removing 2, 3, and 4 all had no impact.

3. HOT COMPRESSION TEST RESULTS:

Cyl. 1 - 136.8
Cyl. 2 - 141
Cyl. 3 - 142.2
Cyl. 4 - 143.6
Cyl. 5 - 146.4

4. At this stage, I swapped fuel pump just to see if results change, and ran the following test.

Hot Compression test 2 (colder by about 5-10minutes)
Cyl. 5 - 147.6

5. At this stage, since I had removed all spark plugs and ignition coils to perform the Compression test, the spark plugs and Pencils have likely been altered on at least once part.

I once again performed a pencil test:

Again,
1. Change
2. No change (fail)
3. No change (fail)
4. No change*(fail) if there was any change, it was very hard to notice.
5. Change

6. Focusing on the failed results, I swapped Pencil 2 & 3 with my spares.

2. No change (fail)
3. No change (fail)
4. Did not retest.
----
While it could be spark plug or pencil that is bad on 2-4, I believe it is likely something else.

High pitched squealing (electrical or air?) could be heard from somewhere in the engine. I can not confirm where.

I took some videos and photos of the sounds in question but the videos are loading. I will likely post them tomorrow or later tonight in a next post.

Attached are the service records I have available & carfax.

--Edit
A mentioned audio and cylinder endoscope video.

[scot850]

Bu pencils, do you mean the coil packs?

Neil

[rtjl]

correct. I have been told they must be grounded with the 10mm bolts, so I will do some tests again today.

Here is another video of the cylinders. are the crowns normal, we are wondering ?

[rtjl]

The pencils were not grounded as suggested. All plugs have an impact now.

I went ahead and performed another hot compression test. Oil temp gauge pictured.

Surprisingly, the spark plugs heads are quite clean now. Pictured, but not clear. They are white

Results are as follows:
Cyl 5: 143.1 (8)
Cyl 4: 146.4 (8)
Cyl 3: 149.0 (9)
Cyl 2: 142.5 (9)
Cyl 1: 149.4 (9)

This time I tested them in the opposite order.

YouTube is currently restricting my upload rate, however the buzzing and hissing I heard is not present when the engine is hot. The clicking on the belt is still present to a degree.
—-
The car is definitely in some sort of limp mode. I was not able to get above 20 regardless of how much throttle I gave it
---
(youtube videos are going to link to a different channel as it already has verification)
It's somewhat hard to tell exactly whats going on.

1) Seems like it has an impact.
2) Seems like it has no impact. This is The same Cylinder Mechanic 2 commented on.
3) Clearly impacts the engine sound.
4) I cannot infer the impact on sound, but the vibrations seem to change.
5) clearly impacts engine sound.

Ill let you form your own opinion:
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Pencil Clip removal test:
https://youtu.be/5RgqmF4W71w
----

Pictured below is some more information. I can hear electrical buzzing on the top right of the engine ( Brake plug ?)

and air escaping & hissing near the air sensor area.

Based on some online videos by robert and the fact air is escaping while engine is off, I believe it could be caused by the engine exhaust fumes return system (PCV) and likely is very dirty and clogged up, which would agree with his comments about short runs as well.

--
I think its worth swapping the throttle body or air sensor to see if theres any differences.
I will try to see if vida will show me any live data before doing any changes.

I cant be certain, but believe the something from the cylinders can be heard clicking rythmically. Probably need another way to confirm or deny this.

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Cold Engine Sound:
https://youtube.com/shorts/xKw47X96RIc? ... zqUHtCmCR4
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Clicking is more noticable cold.
----
Warm Engine Sound:
https://youtube.com/shorts/j9NkjozBfzk?feature=share
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Most of the earlier sounds have disappeared except the ones pictured in the diagram below.
---
Warm Compression Test Crank Sounds:
https://youtube.com/shorts/A2FL2KBlGps?feature=share
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[rtjl]

It initially sounded like there is pressure build up that is slowly released while the car is off. I would need to replicate and find a better angle to demonstrate it, but im not sure if its currently present anymore. There were several loose hoses around the system.

when the ignition is on and the engine is not running, the following is heard:

High pitched whine from system. Buzzing from arm between throttle body and air sensor. Air tube between engine and plastic air hose is vibrating.video attached

https://youtube.com/shorts/3tJFmZ0Gm8E? ... ixE82GuhTF

---

small update.

I've taken a bunch more photos and videos, but will will save the info for when I am looking to replace more things (hoses, cables, etc)

I have reconnected any cables/hoses related to PCV that seemed loose or were not completely attached, replaced the Throttle body and air sensor, and replaced throttle body gasket with an OEM gasket.

The vehicle is certainly functioning far better, but seems to still be a in a psuedo limp mode (can now get the car up to 50-60km/h)

The throttle seems a little 'jumpy' going forward or backwards. Feels like a pulse of power. Occurs during braking as well.

The engine still shakes very slightly, but I am concerned with a potential metal rubbing sound from the engine. (cylinders or other part may have too much 'play' movement occuring)

Video of sounds i'm hearing from engine.
https://youtu.be/wi2dqWmXyRM?si=SrpVI85wWyM97cCm

(when i say 'this thing gives' in the video, im reffering the responsiveness of the torque that Im not used to. the excitement is a little difficult to hide :tounge_smile:)

The previous codes are currently not present. Today, i will try to work on the following:

ECM-4038 Breake vacuum - too low vacuum.
The brake requires a lot of effort to operate.

A quick online search returns the following websites and error info:
https://www.dtcdecode.com/Volvo/ECM-4038
http://www.bsr.se/docs/man_diagnos_uk.pdf

Combining all the feedback I have received on this issue;

diagnose:
plugging and unplugging the brake vacuum hose and seeing how it affects the running

check locations:
-brake master cylinder check
-3/4 inch rubber hose between brake servo*(?) and front left of intake manifold near battery
-check valve on brake booster
-vacuum pipe possibly leaking to the booster. Or the plastic one way valve in the booster may have failed.
-brake booster pipe

I have found the following attached schematics that seem related to the topic.
I aim to get underneath the car with the wheel removed and inspect the lines one side at a time.

I have found that the recommended information on torquing the the wheel lugs to be 81 PSI, but have also read numbers such as 100 or more.
Any comments on this are appreciated.

[abscate]

That’s the hydraulic part of the brakes, not the vacuum part. All of the vacuum part is in the engine compartment.

A fat hose comes off the intake manifold to the right side of the engine/ car* and then goes backwards plugging into a large sauce pan sized black cylinder on the firewall, in front of the driver. Check that hose for leaks.

That second diagram is for an air pump thst your car doesn’t have, it’s a -1998 fitment.

[rtjl]

After confirming software compatibility and viewing VC7200 counters, I felt confident that that softwares are compatible and performed an ECM reset. (3minute interval procedure)

At the end of said procedure, I was asked if the ECM-4038 error was still noticeable. Since I was not sure, I closed the window (x)

After the reset, the system requested a 20s idle procedure for code reading.
I am no longer faced with error code ECM-913F, so I believed it was successful. Will have to see.
----
After restarting vida and requesting a fresh read, the error returned.
I'm probably going to consider cleaning and swapping back to the previous ETM if no other procedures work.

Attached are some videos of live data. Theres also a photo attached about potentially cleaning out the ports of the connectors. This is one of the same ports/devices that is making the electric whining noise.

(1/4)
ETM TP sensor 1, ETM TP sensor 2, ETM Intake throttle desired, ETM accelerator pedal, ETM Absolute Throttle position
https://youtube.com/shorts/JPA5kewf66M?feature=share

(2/4)
(as mentioned in 1/4, as well as: ECM-Oxygen sensor front (3 different readings), ECM-MAF voltage, ECM-MAF g/s)
https://youtube.com/shorts/xVWCjpODxBo?feature=share

(3/4)
(as mentioned in 1/4, as well as: ECM-brake pedal position, ECM brake pedal position sensor)
https://youtube.com/shorts/TQY5FZC-gqU?feature=share

(4/4)
(as mentioned in 3/4, as well as: ECM battery voltage, ECM Camshaft position)
https://youtube.com/shorts/E2Hs2bmV0-U?feature=share

I will review the data again and search for some relevant info.
Thanks for the heads up.

Have a good Thanksgiving weekend abscate (and Niel.), and to any readers.
Jonathan

Thank you all for your help so far.

[rtjl]

Hello,

I found the ETM test section, and it said the ETM software was up to date and compatible. I performed the ETM test and the result says the sensors max difference is 0.48 degrees. It states that the maximum varience permitted is 13 degrees.

Image 1: ETM Software part number (updated confirmation)

Image 2: ETM live readings at no throttle (written below)

no manual throttle readings.png (105.21 KiB) Viewed 179 times

Image 3: ETM live readings at full throttle (written below)

full throttle readings.png (119.43 KiB) Viewed 179 times

Image 4: ECM-913F Unselected CSC drop down symptom options

Image 5: ECM-913F CSC symptom specific info (idling, uneven idle, AE)

Image 6: ECM-913F CSC symptom specific info (Driving, hesitates/surges, at steady speed, BV)

Image 7: 720A code reference. (no issues)

Image 8: ETM test results graph (maximum difference shown 0.48 degrees)

Image 9: ECM-913F Potential sources

913F potential sources.png (698.36 KiB) Viewed 179 times

I checked the ETM throttle position sensor, throttle absolute position, intake thrtottle / desired position, and accelerator pedal live data.

*Again I see that ETM-Absolute throttle position begins at 21.18% instead of 0%. *

At no throttle, the readings are:
TP Sensor1: 31.41 degrees
TP Sensor2: 31.73 degrees
Absolute Throttle pos: 21.18%
Intake throttle desired position: 10.4%
Accelerator pedal: 8.19%
--
at full throttle, the readings are:
TP Sensor1: 94.66 degrees
TP Sensor 2: 94.44 degrees
Absolute Throttle position: 99.94%
intake throttle desired position: 86.82%
accelerator pedal: 68.64%

I am able to view the dropdown options under unselected CSC which cover different symptoms and list of items it wants to check to verify symptom, but it does not update from the 'checking' message phase. I am able to manually click on them and confirm/deny the question, but I am not sure how to progress.

I do not have enough information to confirm the points:
-checking freewheel on a generator, checking fuel pressure, checking ignition spark.
-Based on previous discussion, we have checked injectors & compression, and a fault has not been assumed.

**---
(1st side note) At first, the idle was smoother than I have ever observed, sitting exactly at 900RPM, and there was no rattling / shaking sounds from the muffler system.

However after approximately 20-30s of idle, the unevenness of the engine begun again, the idle RPM statred to vary, and the muffler shaking and rattling sounds crept up to its regular behavior.

(2nd side note) I have read of exhaust systems providing precise back pressure to the engine to properly match what the system has been tuned for. My exhaust/ muffler is heavily damaged and full of holes, as well as shaking.

The condition of the attachment of the exhaust system is unknown to me at this time.

(3rd side note) I have read of some exhaust systems being designed suboptimally, causing exhausts to shake more, unattach, or touch the ground (V0lv0 was mentioned specifically), as well as catalytic converters building up enough debris and pressure within the cat to cause issues, as well as some breaking entirely into multiple parts and causing a violent rattling and shaking. My exhaustsystem seems to be experiencing violent rattling and shaking, and the smell of fuel is pretty substantial.

I am not able to determine if any of my side notes are relevant, but I am not sure if ive stressed them so far.
**---

the ECM 913F error code went away when reading delivery. However after another IS update and read all, it returned.

After another 3minute ignition off guided period, I performed another IS update and the results were such that there was no faults in delivery, ECM913F was present in unselected CSC, and ECM-720A and ECM-913F present in Initial state.

*Info for ECM-720A states this code shows up when the engine is started while the ignition has been on for too long without ignition being turned off. This matched my procedure; I should have powered off entirely before trying to start engine. I have no issue starting the car at this time.*

***However, now I am seeing ECM is greyed out in delivery, unselected CSC, and initial state. I have not witnessed this before.***

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At this stage, I believe:

-Current active codes are ECM-913F, which initially showed ETM module as red, but now the ETM module is grey and the unselected CSC displays the error code as green.
-I cannot verify if the ECM-913F issue has been resolved, however the symptoms are still present after allowing for a brief idle, despite color of icon of error.
-The ETM software appears compatible, and the sensors are within 13 degrees of each other. (0.48 degree difference stated)
-The absolute throttle position does not fall below 21.18% with throttle entirely depressed. (should be 0%?)
-I am unable to clear or verify ECM-913F code with what I know so far.

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Please let me know what you think i should try next, what info I can provide, or if there is something I could do to improve info presentation.

your feedback is appreciated.

Thank you,
Jonathan