I have a 2007 S40 manual transmission that sputters every now and then, and the "Check Engine" light will come on and eventually go off again, sometimes staying off for months.

Three years ago, the Volvo dealer checked the engine and found the following valve (?) readings suggesting the beginning of the end of the car engine: 150/150/150/110/110.

I keep engine coolant in the trunk and check frequently to see if the level drops. Only three years, I've only added a little and still have most of the same coolant left in the container (zero blue muffler smoke).

After the last inspection, I got the oil and filter changed as well. They placed a lower grade of oil in instead of the synthetic brand. The car from that point on began noticeably sputtering again. The code usually points to spark plug #3 misfiring. The car passed Volvo inspection the past three years. I only drive it on Sundays (15 miles round trip). It has 154,000 miles on it, and I'd rather avoid putting more money into the vehicle if needs a need engine. I'm wondering if this could be some other issue that could be resolved easily?

I'll be calling Volvo as well. Thanks if you have some insight. The internet search is suggesting adding a cleaner as a solution for a clogged fuel system.

 

The readings you have are compression for each of the cylinders. The two low readings are far from ideal, but I wouldn't get my knickers in TOO tight a twist if it's normally running well otherwise.

The misfire on cylinder 3 could have something to do with the low compression (if the problem is rings, which could allow oil to get by the rings and foul the spark plug). Or it could be just bad (worn out) spark plugs. If you haven't ever changed plugs, that's a no-brainer, and might well fix your misfire.

Also, if you've never had the timing belt changed, it's well overdue, and if it were to break, your engine becomes a giant doorstop. OTOH, it's not a cheap job, and if you really do 15 miles a week... your odds of it breaking on any given Sunday (pun intended) are low.

I'd suggest doing your next oil change a little earlier than normal and might suggest a heavier weight synthetic (could help with oil blowby on those two cylinders).

And yes, using a can / bottle of fuel system cleaner isn't a bad idea at all, and may well help if your problem is related to a dirty injector. Or not. But since the cost and effort involved is so low, there's no reason NOT to put some fuel system cleaner in the car. At 15 miles per week, it takes quite a few weeks to go through a tank of gas, so I'd recommend using really good gas (with the best cleaners), and only filling up 5 gallons when you do (which should last more than a month), just to keep the gas as fresh as possible.

 

you didn't mention if you have an NA or turbo. I'd probably discount the compression test since its three years old and the car ran fine following. Most likely that was done on a cold engine. If you really are curious about the fitness of the block, go out to Autozone and rent/borrow a compression test guage, find a Youtube vid for instructions and see what you get. While your doing that, you can also inspect/replace the plugs (go OEM - more expensive is not better for these cars) and inspect the wire harness to the coils. I'd also consider buying a new coil and drop it on cylinder 3 while at it (keep the old for a spare). As to the oil, I'm not sure what you mean by lower grade of oil. By that do you mean traditional dino oil not synthetic? Funny thing is, that would probably help the compression not lower it... Did you record any other codes other than a misfire on #3? The misfire could be weak spark, or a fuel metering issue. The suggestion to a clogged fuel system is a bit general. You can throw in a can of Techron to see if it cleans the injectors or you can run a few tankfuls of name brand premium with its added detergents. It may be that you also have a fuel pressure issue (sensor/pump/filter) but that's another test.

 

The Volvo service technician emailed all of the codes shown. The mechanic noticed the stuttering and thought that the misfires and started burning multiple valves or something along those lines. The solution, he said, would include costly repair and machining the valves. I got the gist that they would rather avoid doing that. It sounds time consuming. He indicated that repairing would not be cost effective.

Meanwhile, I'm wondering about the next step. Another mechanic who's unfamiliar with Volvos told me that the car might be a good candidate for Blue Devil sealer or some other product. I've only viewed the YouTube videos. At this point, I'm thinking it's worth a shot, although I'll probably get a local mechanic to do it, unless it's doable without a hassle. Otherwise, repairs sound like it's $4000-$8000 (without a guarantee something else will require fixing).

I'm able to manage without a vehicle for a while if I have to do so. Everything is in walking or delivery distance.

 

The assumption here is that your compression test shows a loss of compression in two adjacent cylinders, which can be caused by a head gasket issue or in rarer cases a crack in the block or head. The second tech has suggested that there are head gasket "repair" sealers (like Blue Devil) that can fix small leaks (you pour it into the coolant). Before you do that, there are some other tests and signs the head gasket has issues - loss of coolant with no signs of leakage, froth in the oil (ie on the fill cap or dipstick), HCs in the coolant (there's a test kit for this), oil in the coolant and a compression test.

If you suspect burnt valves, Blue Devil won't help you, but a leak down test will. Say you have low compression doing a "dry" compression test - next test is to determine whether the compression is going out via the rings (wet compression test does this), the valves (a leak down or inspection cam can help) or the head gasket (other tests like an HC test will show if the leaked out exhaust is getting into the coolant).

So lets say it is a head gasket or burnt valves. The cylinder head needs to come off and either replaced with a used part or rebuilt. That's when you'd expect a $3000 cost. That says to me its worth investing $100-200 or so in getting a proper diagnosis and a descriptive set of test results back. Any shop would be able to do the compression/leak down/ HC test as well as test for fuel pressure and other possible root causes.

 

A trusted local mechanic suggested getting a new engine if the Volvo technicians were correct about the valve problem. I agree that more tests would be wise (leakdown) before going further.

The current engine in the vehicle has 150,000+ miles. I've kept up with all services, including timing belt change at 100,000+

The replacement engine the mechanic found while talking to me on the phone has 98,000+ miles and would cost $2800 + $1000 (approx) labor, providing it requires one after further tests (leakdown).

Questions:

I'm wondering about the hidden issues of replacing an engine.

1. Will a new timing belt be needed? ($$$)
2. Should I replace, repair, or check other parts as well while the engine is being replaced (O2 sensor, broken air conditioner or recharge needed, aging struts, catalytic converter—or just wait until each part fails)




I saw two other interesting options for three years of worry-free maintenance that also caught my attention:

1. Pay cash for a new or slightly used vehicle with a 3 year warranty (Nissan Versa 5 speed = $15,000)

or

2. Lease a Nissan Leaf for $89 a month + $1500 down for 24 months.


UPDATE:

Both options are currently unavailable due to a nationwide car shortage. It's either repairing the Volvo ($4000+ with whatever else requires fixing next) or going carless until the car market changes.

 

I'm not at all convinced this car needs an engine, based on a simple misfire and the years-old compression test. Do the "real diagnostics" as mentioned by mt6127, and see where you are then.

On a relatively low-value older car like this one, if you DID find out that there's a head gasket (possibly) issue, I'd be willing to try using the pour-in head gasket fix. Yeah, it's not a "real fix" but if it gives you a few more years for chump change, it's a win/win. If it doesn't work, it's just $20-30 to roll the dice.

Another option is to simply look for another similar vehicle. A 30 second scan of the local (Phoenix, AZ) craigslist ads shows several options in the $2,500-4,000 range. And of course, you could always sell the current car to recover at least some of that. Yes, buying a used car does come with its risks - and most of them will need a timing belt, since folks tend to ignore that.

And finally, if you DO opt for a new engine, I'd swap the timing belt while it's out of the car, where it should be MUCH easier (cheaper). This should include the tensioners, water pump, and of course the serpentine belt and its tensioner(s) as well.

 

I finally found an independent Volvo mechanic shop that just took a look at the S40 after Volvo dealerships on two occasions suggested engine failure due to a head gasket.

Summary from current independent Volvo mechanic:

A catalytic converter problem caused the misfiresS40 estimated to be roadworthy again in three weeks without engine replacement. 😊😊😊 Issue was a clogged(?) catalytic converter preventing airflow to engine. Leakdown test (now within specs) after failing at the previous mechanic who had only worked on a few Volvos in his life. Compression test passed - btwn 140-150
The previous mechanic said tge lowest cylinder was at 50 Mechanic said they would do a road test to make sure they found the right solution.

Total cost seems minute compared toa new engine or head gasket rebuild.

Hoping to be on the road safely again soon.

 

FWIW, it's quite possible that misfires caused the clogged cat. When a cylinder doesn't fire, the unburnt gas flows into the cat, where it's burned. It can handle a fair amount of raw gas, but eventually it can clog it up. Same with an internal (into the combustion chamber) oil leak.

And to be pedantic, the clogged cat actually prevents airflow FROM the engine (out the exhaust pipe). If it's clogged enough, it could mess up the compression test I suppose (but I can't imagine the engine actually running if that's the case). Sounds like you found the right mechanic.

 

Thanks. From what I understand, passing the compression and leak down test indicate something other than having a head gasket problem. I certainly hope I found the right mechanic to get and keep the vehicle running safely again. If it were a head gasket, I understand from the mechanic that rebuilding it would be the better solution than finding another used engine.

See photo of previous non-Volvo mechanic's estimate for a used motor.

 

you can do your own parts sourcing (without the warranty of course) - check out car-part.com to see what used engines price out at directly from the yard.

 

After speaking with the mechanic, the repairs have all been made and the only thing they are waiting for is the $1200 work required to fix a brake pedal that creeps/sinks too far down when pressed.

As for the main issue with the engine:
a. installed new catalytic converter other than the Volvo more expensive unit

b. replaced spark plugs

c. replaced spark plug coil (#3 spark plug coil had previously been replaced years ago after codes kept reading a misfire for #3 spark plug)

d. leak down and compression test within acceptable range (140 - 150 for compression test)

e. replaced passenger-side mirror that had been fluttering after the glue failed to hold it in place)

Total cost including taxes: $3072.00. (includes the new hydraulic seal and software upload for braking system)

What I've learned so far:

"In the multitude of counselors there is safety" if they include knowledgeable Volvo owners and mechanics.

 

update and final statement

 

update and final statement

 

Update on fix for S40 sputtering engine

In case this helps others, I will update how the vehicle drives periodically after the local Volvo independent mechanic made repairs.

Performance: Car seems in good condition without any noticeable misfires or sputters. When reved up between shifting (a manual), the engine still reminds me of the faster performance cars, which makes it so fun to drive/shift from 1st to 2nd. I stay within the speed limit, however. 🏎

Note: I did have to get the parking brake repaired, and this led to replacing the ABS control module. The mechanic ordered a part through Erie Volvo used parts ($150 for the used part, which surprised me after seeing the bill). The part they installed still failed to work satisfactorily (mushy brake pedal that sinks low), and they had an issue trying to replace the rear calipers to fix the parking brake. By the way, they used reconditioned calipers.

"The car is 16 years old."

Should I suggest using only Volvo new parts, especially for critical areas like brakes? The car has 156,000 miles on it so far.

 

I don't know... it sounds a lot like the mechs were guessing what was wrong with the brakes (at your expense). Not sure what connection there is between a bad parking brake and the ABS (totally separate systems). Maybe they just installed a bad caliper, or didn't properly bleed the brakes. Or there's another issue (bad seals in the master cylinder will cause the kind of symptoms you're seeing, for example).

 

The "at [my] expense" part caught my attention, too, when I got home and realized whatever the mechanics did made the parking brake worse. The owner of the business explained afterwards that they did have trouble getting the braking repairs done, and he added that returning the vehicle for them to troubleshoot again will be at their expense since they guaranteed the labor and parts ("two years").

I skimmed your comments and found something more important to me:

"Sounds like you found the right mechanic."

The long-term results will verify the truth of that statement. I'm hoping more than a just a few good mechanics remain.

Just wondering how you learned so much about Volvos? Did you work at as a Volvo mechanic somewhere?

Thanks for the tip about the master cylinder and the distinction that the ABS control unit/module has little in common. One of their mechanics, as noted in the previous screeshots of the billing receipt, stated that the "hydraulic seal" required repair in the ABS control unit/module.

I have only what I can query or post online or talk to other mechanics I know to help me figure out the most accurate assessments.

I will know better after returning the vehicle Tuesday for a loaner car. Thank you for helping.

 

Mechanic stated that he replaced the 'reconditioned' rear calipers with new Volvo calipers. So far, the vehicle holds easily when parked on a hill. He also cleaned the front calipers as well.

His insight:

The vehicle could last another 3-5 years or longer. He stated that I need to drive it more to avoid parts rusting or going bad. Currently, I've driven fewer than 3000 miles a year for the past few years, mostly on Sundays.

 

[img alt="ECM 3502
ECM-P3503

Question 1: Is the P simply a typo?

Question 2: Does this sound like an ignition coil issue again?

The mechanic who replaced the ignition coil a couple of years suggested replacing all five ignition coils ($600 - $700)

Another Volvo mechanic thinks a flimsy harness wire needs to be checked and, if worn, rewired or replaced.
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ECM 3502 ECM-P3503 Question 1: Is the P simply a typo? Question 2: Does this sound like an ignition coil issue again? The mechanic who replaced the ignition coil a couple of years suggested replacing all five ignition coils ($600 - $700) Another Volvo mechanic thinks a flimsy harness wire needs to be checked and, if worn, rewired or replaced.

 

there's two standards for defining OBD2 fault codes - industry and vendor proprietary. The industry standards use a letter followed by a four digit number where the letter indicates which system (onboard computer) is being queried. The P stands for powertrain (engine and transmission) systems, B for body, C for chassis, and U for network and wiring systems. For example, your ABS system would throw Cxxxx codes but an engine/emissions issue would throw a Pxxxx code. This also explains why cheaper OBD2 readers don't report on brakes or airbag warning lights since they don't query those computers Proprietary codes are vendor defined but will include the industry codes as a subset so a tech using a VIDA DICE tool will see all the codes that your hand held Harbor Freight unit and then some. For most basic CELs, the $29 hand held units are fine. for deeper diagnostics then you'd need some pro gear that can run $$$ more.