Our 06 grand caravan on acceleration will spark knock and sometimes it feels like it has a slight miss as well. Plugs and wires are pretty new, it's been well maintained and has no pending or permanent codes. Where would you start? Running 89 does seem to help but it shouldn't need 89 to run ok. Thanks for all the input!
Spark knocking on acceleration grand caravan
- Thread starter ram_man
- Start date
Start with EGR. Insufficient EGR leads to spark knock. EGR leak causes poor idle.
It was replaced less than a year ago because it threw a code for it. But maybe it's failed again?
Interesting…
What was replaced? EGR Valve? Control solenoid? I don’t know much about your engine, but in general, codes only tell you that the computer is unhappy, not that a part needs replacing. Codes are a start.
You might, for example, have an EGR leak around that new part. It may not be EGR at all, but a faulty EGR Valve will cause your symptoms.
What was replaced? EGR Valve? Control solenoid? I don’t know much about your engine, but in general, codes only tell you that the computer is unhappy, not that a part needs replacing. Codes are a start.
You might, for example, have an EGR leak around that new part. It may not be EGR at all, but a faulty EGR Valve will cause your symptoms.
Did they just replace the valve or did they also clean out the carboned up passages under it?
My parents owned a 2005 Chevy Uplander (minivan) for about 7 years. It pinged (spark knocked) for at least 3 years and we never figured out what caused it. New plugs and wires never resolved it. A few trips to the shop and they could never figure out what was wrong. Never threw a code either. My mom always filled up with mid grade or premium once the issue started and that did help, but it never fully resolved. They put a good 30K - 40K miles on it while it had this issue and it still ran fine when they sold it with 170K.
Check the EGR passages for clogging.
I agree check EGR first. But i have to wonder why the ECM is not pulling back timing. The knock sensor should influence the ECM to pull back timing.
Don't be afraid to look at the electronic throttle body. If the fine toothed gears in the body or the servo motor start to fail,the throttle plate slips a little bit and can give a feeling of a miss under load. Not so much a knock though. Sometimes not enough to throw a code. Pretty cheap p,ugly and play replacements out there. Inner working are non serviceable. Except when you open them up for autopsy.
Nick1994
$100 site donor 2024
Try 91 octane for a more definitive assessment. My 15’ Sonata pinged on 87, so I ran 91 (no ping). New plugs didn’t help.
Yes its likely "EGR Low Flow" codes are from clogged passages, not the valve itself.
my 2001 ate plug wires surprisingly quickly, don’t assume they are ok - check them.
we had a small inline vacuum valve get sluggish which caused roughness during tip-in. Don’t recall if it was pcv or egr related, but do recall it a $20 fix.
we had a small inline vacuum valve get sluggish which caused roughness during tip-in. Don’t recall if it was pcv or egr related, but do recall it a $20 fix.
How many miles on engine?
What is the mileage on the spark plugs? Have you pulled them to inspect their condition?
Try supreme gas and see if that stops the knock. If not, time to consider other possibilities, like it’s not spark knock you hear.
What is the mileage on the spark plugs? Have you pulled them to inspect their condition?
Try supreme gas and see if that stops the knock. If not, time to consider other possibilities, like it’s not spark knock you hear.
3,000 miles pulled a few all looked good. Vehicle has 121,000 miles. It's definitely spark knock
Then it should be easy to resolve. Run higher octane gasoline and/or eliminate the hot spots that pre-ignite the gas.
If the engine has knock sensors, and they are working properly, you should not be able to hear any spark knock. It would be advisable to figure out why they have not been able to arrest this behavior, as something is clearly going on with them or the PCM’s ability to adjust ignition timing in response to the knock.
Get a code reader that can read live data. BlueDriver calls it mode 6. This will tell you which cylinders are missing even without a code. Then swap wires and see if it follows.
3.3 or 3.8L ?
I experienced similar pre-ignition (pinging) in a Mazda van. I tried premium fuel, an octane booster additive, and cooler plugs, none of which helped. The out-of-sight out-of-mind PCV valve turned out to be blocked. I'd discovered it when chasing oil and coolant leaks.
A new PCV valve cured the pre-ignition, and improved driveability immensely.
A new PCV valve cured the pre-ignition, and improved driveability immensely.
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