How is BOSCH quality?

steppinthrax

Diamond Member
Jul 17, 2006
3,990
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So I bought their spark plugs twice and a wire set from them. All of it goes bad within 2 years or so. I put the platinum tip plugs in an old Altima I had, after a year or so I was getting intermittent misfire. I just today replaced the 3 YR old BOSCH wire set on my Camry. Was getting a SES light and misfire on 2 and 3 on the OBD scanner. I also remember replacing BOSCH plugs on my Saturn 5 years ago.
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
34
91
If the mixture is crap, any plug is going to wear out quickly.

I've never had an issue with Bosch parts unless I used the wrong part in the wrong application. I'm inclined to believe the problems you experienced were user error and/or the result of other mechanical issues.

ZV
 

bruceb

Diamond Member
Aug 20, 2004
8,874
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Depending on the car, I use AC Delco, Champion or NGK ... none of my cars would have a Bosch plug. At one time Bosch products had a bad reputation for failure. That may have gotten better, but I am not sure.
 

wirednuts

Diamond Member
Jan 26, 2007
7,121
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bosch makes good stuff. if you keep having problems then get your engine to stop running rich or hot.

and dont waste your money on expensive plugs. just buy brand name cheapies (champion) and replace them every few years. this will eliminate spark plugs getting seized into the block (which is a nightmare).
 

steppinthrax

Diamond Member
Jul 17, 2006
3,990
6
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These were with 3 different vehicles, 3 were using BOSCH plugs (all gone bad). I would get a real rough idle (missing). I replaced the plugs in both my Saturn and Nissan to the factory plugs (not BOSCH) and it never happend again. I just had (today) my BOSCH wire let go bad. Was getting an SES light read the code with my OBD reader (P303, P302, P300). Was getting missfire in 2 and 3. Moved the wires around to troubleshoot, found it to be the wires. Replaced the wireset, fixed....
 
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steppinthrax

Diamond Member
Jul 17, 2006
3,990
6
81
bosch makes good stuff. if you keep having problems then get your engine to stop running rich or hot.

and dont waste your money on expensive plugs. just buy brand name cheapies (champion) and replace them every few years. this will eliminate spark plugs getting seized into the block (which is a nightmare).

Your plugs get seized to the block (lol)...
 

Bartman39

Elite Member | For Sale/Trade
Jul 4, 2000
8,867
51
91
In general how long are plugs and wires supposed to last.

Platinum`s and the wires should make 100K... Just about everything these days has issues... I recently put 2 sets of Motorcraft platinum`s in a V6 Ford 1/2 ton and both times I had issues with shorted or misfiring plugs at startup... Put a set of Bosch platinum`s in and been running smooth and strong every since... Out of all the brands I have used the best and least problematic are NGK`s... The seem to work good in anything and real good in my Mercury outboards which are very picky about plugs...


As for plugs seized in the heads I think he is talking about the Ford 3 valve engines which had this problem with the factory installed 2pc plugs... Champion makes their version in a 1pc design which eliminates the problem...
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
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At one time Bosch products had a bad reputation for failure. That may have gotten better, but I am not sure.

I've never heard of any such reputation for Bosch parts. They've always been well-respected for European cars. People bitch about certain parts in old cars but any electrical bit that is 25-35 years old is going to be sketchy, especially if it's in a car with 100,000+ miles and has experienced the weather and temperature fluctuations that cars do.

Responding to the question of how long plugs and wires are supposed to last, that depends entirely on the condition of the vehicle and how well it's maintained. If you're burning oil, if the mixture is off, if there's a head gasket leak, they'll die fast. If not, they'll last anywhere from 15,000 to 100,000 miles depending on the type of plug. Copper plugs in turbo engines only last about 15,000 miles, platinum plugs in low-stress engines can last 100,000 miles (my opinion is that they should be replaced every 50,000 miles but that's just me). If you have the wrong heat range of plug it can really throw that off as well.

Wire sets should last 50,000 to 100,000 miles, but that's again highly condition-dependent. If you keep the engine bay clean they'll last longer, if not, less long. If you don't route them through all the clips or if a clip is gone, they can vibrate against things in the engine and the insulation can abrade. Again, it all depends on the specific car.

ZV
 

T2urtle

Diamond Member
Oct 18, 2004
3,432
3
81
i normally run with what comes with the car orginally. which are NGK for the most part. Use their wires as well.

I've pulled some bosch plugs out of some cars and never heard the owners say it ran better or worst. In a jam i would use them.

I dont like their filters tho. I think there are better options for the price.
 

Bignate603

Lifer
Sep 5, 2000
13,897
1
0
bosch makes good stuff. if you keep having problems then get your engine to stop running rich or hot.

and dont waste your money on expensive plugs. just buy brand name cheapies (champion) and replace them every few years. this will eliminate spark plugs getting seized into the block (which is a nightmare).

No way I'm putting cheap stuff in my wife's van. It's an ordeal to get to the back bank of plugs so I want to do it as few times as possible. With a good set of platinum plugs you only need to change them once, maybe twice, over the life of the car.
 

kornphlake

Golden Member
Dec 30, 2003
1,567
9
81
No way I'm putting cheap stuff in my wife's van. It's an ordeal to get to the back bank of plugs so I want to do it as few times as possible. With a good set of platinum plugs you only need to change them once, maybe twice, over the life of the car.

In a 4 banger it's pretty easy to change the plugs whenever you get the urge, in any modern vehicle with a v6 it's really worthwhile to get longer lasting plugs. It took me about 4 hours to change the plugs, wires cap and rotor in my wife's van this weekend, most of that being time to change the plugs. I used AC Delco platinum plugs and expect they'll last 70k miles or the remaining life of the vehicle. In my saturn I'll replace the plugs every 15k miles or so with cheap copper plugs, but it only takes about 5 minutes, the ignition system in that car has a waste spark on the exhaust stroke which eats up platinum plugs, they don't last as long as the copper plugs. Moral of the story is, use whatever plugs the OEM uses and you'll have the best results.
 

exdeath

Lifer
Jan 29, 2004
13,679
10
81
If I recall the 4th gen (?) Bosch 4 channel ABS controllers had issues. Had one go out in my Cobra, kept getting C1805 ABS/PCM mismatch codes and intermittent light, replacing the module finally fixed it. It seemed to be a wide spread problem on many makes and models of cars, and there are dedicated websites that offer services to fix them.
 

zerocool84

Lifer
Nov 11, 2004
36,041
472
126
and dont waste your money on expensive plugs. just buy brand name cheapies (champion) and replace them every few years. this will eliminate spark plugs getting seized into the block (which is a nightmare).

That's why you put anti-seize on the threads when installing new plugs.
 

alkemyst

No Lifer
Feb 13, 2001
83,769
19
81
Bosch are good. However; I have found they are not a subsitute if your OEM is NGK.

my car uses NGK's I tried the Bosch equivalent and got misses. Regapped them and it still missed.

Put NGK's back in and all was good.
 

Vette73

Lifer
Jul 5, 2000
21,503
9
0
I haev used lots of bosch parts and never had any major issue. Not a fan of their Plat plugs but if they had that many problems I doubt they still be sold today.
 

CraigRT

Lifer
Jun 16, 2000
31,440
5
0
I would not touch anything from that brand.
Pretty much no exceptions maybe minus wiper blades.
 

Viperoni

Lifer
Jan 4, 2000
11,084
1
71
Their plats are hit and miss. My dads VQ35 did NOT like Bosch Platinum +2's, piss poor mileage but the performance was fine, but worked properly with NGK plats.

My Echo on the other hand seems to have picked up a couple ponies after going to Bosch Platinum IR (4 ground electrodes + iridium on the center electrode) from NGK Coppers.
 

Howard

Lifer
Oct 14, 1999
47,982
10
81
Their plats are hit and miss. My dads VQ35 did NOT like Bosch Platinum +2's, piss poor mileage but the performance was fine, but worked properly with NGK plats.

My Echo on the other hand seems to have picked up a couple ponies after going to Bosch Platinum IR (4 ground electrodes + iridium on the center electrode) from NGK Coppers.
Weird. Seems like their +2 would be the best since it has minimum interference with the flame propogation.
 

pcgeek11

Lifer
Jun 12, 2005
22,103
4,889
136
If I recall the 4th gen (?) Bosch 4 channel ABS controllers had issues. Had one go out in my Cobra, kept getting C1805 ABS/PCM mismatch codes and intermittent light, replacing the module finally fixed it. It seemed to be a wide spread problem on many makes and models of cars, and there are dedicated websites that offer services to fix them.

That is some old stuff Gen 4. They are starting the 9th generation assembly lines up this year.
 

CraigRT

Lifer
Jun 16, 2000
31,440
5
0
Weird. Seems like their +2 would be the best since it has minimum interference with the flame propogation.

The VQ really likes its standard double platinum NGKs (stock)
My car (2002 Maxima) ran like a top and pulled like a train with those plugs!