Partsology sent me a slightly different timing belt, wrecked my engine
Posted by SoneiOTree@reddit | projectcar | View on Reddit | 68 comments
Just a little story/word of caution. I ordered a timing belt kit for my '88 300ZX from Partsology. They sell cheap parts but I've successfully worked with them in the past on these specific cars.
Water pump goes on well, t belt tensioner goes on well, t belt takes a little more force than I would expect to get on. I notice this, take it off, and compare it to the belt that came off. Same size, exact same tooth count. So I put it on.
Turns out, it was a belt kit for a VG33 instead of a VG30. I discovered this when I first started cranking the engine. It definitely sounded rough and didn't idle. Tried seeing what else might be wrong, causing it to not idle, and eventually, I'm hit with a giant no-start.
I pulled the valve covers off, and the rocker arms are floating over the valves on one cylinder embankment. I've yet to take that cylinder head off, but I am assuming I have bent valves at a minimum. I really hope I don't have damaged valve guides or pistons...
The ONLY difference between the two kits is that the VG33 belt has rounded teeth while the VG30 belt has square teeth. Everything else was exactly the same. Water pump, tensioner, belt size, belt tooth count.
So yea, just wanted to share my misfortune. I guess always check everything when it comes to parts like these. Do it right, or pull your cylinder heads off. So far, Partsology has told me they would only give me a refund on things if I send them back (water pump and tensioner are good and installed). Some replacement valves or help with any other damaged parts due to their warehouse mishap would be nice, but no luck so far... Probably won't be working with them again.
NissanTouge87@reddit
The vg30 and vg33 heads are very nearly identical. As in, interchangeable. The timing belt tooth profile isn't likely to have caused the damage. (Source: owned and modded and did belts on both vg30s and vg33s)
The belt being hard to get on would have been the first indication. Timing belts have to keep everything rotating withing half a degree or so, at up to 6000rpm. If it was tight going on, something was off.
Also, not trying to sound condescending or belittling. Genuinely wanna see you succeed, I love the z31s.
SoneiOTree@reddit (OP)
I'm not sure what else could have been off with this process at all. Genuinely. The timing belt I received had the exact same tooth count and was the exact same size. Checked all of it and made marks to make sure I wasn't counting wrong. Lined up all TDC indicators, further verified TDC, and rotated the engine to ensure valves weren't colliding prior to reassembly.
Another difference in the belts was the depth of the teeth. The new belt's teeth were protruding slightly more than the original OEM belt.
NissanTouge87@reddit
That would explain the tightness, but not the bent valves. Just curious on what brought you to this point? Just maintenance on the belt? Engine issues? I ask because I've mistakenly freshened up heads and timing kits just to find out the block was borked.
SoneiOTree@reddit (OP)
Maintenance on the belt. The OEM belt looked fine, but the car was neglected for years prior to my acquisition. I also replaced all soft fuel lines, steering rack, several power steering pump hoses, and the tie rods.
The engine ran somewhat fine prior to the timing belt. I say somewhat as in it burned a bit of oil, could use a general tune up, etc. I felt no issues as far as prior low comp or anything else.
NissanTouge87@reddit
Maybe the rings gave out? Do you have access to a leak down tester to see where it's losing compression? Since the belts off and valve covers are off. Pull the cams so all the valves seat and do a leak down and compression test. Relatively quick tests that will give you a definite answer. The rings might have just gave way, too
cheeseshcripes@reddit
I've had one of these cars back in the day and had timing issues with it too. If you used the timing marks that are on the belt itself, they are set up for a Pathfinder engine, and I do believe, don't quote me but I'm pretty sure, the Z31 engine is 1 tooth different on the left bank then the Pathfinder. You can tell because it's impossible to time the distributor correctly if everything is lined up and triple checked. It'll adjust to it's full stroke and not time, then you can pop it out and jump a tooth, and it won't time set to the full stroke the other direction. There are many, many accounts of this online.
And if that sounds ridiculous, just know for the next generation of engine, the VQ30DE, the VQ30DE and the VQ30DE-K are 3/4" different in width measured from the exhaust ports, and the DE-K is supposed to be a slightly improved version of the DE.
SoneiOTree@reddit (OP)
Every timing belt I've bought for these cars in the last 3 years has not had any marks as they are non-OEM and used for other models typically. Like I've done in the past, I counted the teeth several times and made my own marks. 40 teeth between passenger/driver cam and 43 between driver cam and crank sprocket markers.
Then-Pay-9688@reddit
Did you document the process (timing marks and what not?). I figure you know what your doing, but if you can prove that you didn't make a mistake there you'd have a better chance of convincing the retailer.
SoneiOTree@reddit (OP)
I did not because I assumed everything would be fine haha
danny_ish@reddit
You say rotated the engine- how many times? How quickly?
We rotate small block chevys for 15-30 min via the oil pump pickup to ensure we still have timing when done
Tema_buraz@reddit
Did you check the tentioner? How'd you put it on? Did it come lose and skip?
JackTheBehemothKillr@reddit
Belt size and tooth count are all there are to drive valve timing. Belt being bigger would have been a problem of wearing into the timing chain covers or something similar.
Unfortunately, I think this is a problem with initial valve timing when you changed the belts.
ineyeseekay@reddit
Would rounded teeth vs square cut potentially mean the belt could have slipped? I'd think rounded teeth would prevent the belt from seating properly, in addition to the tightness potentially being an issue itself.
MachWun@reddit
Rounded teeth were a later innovation that kept the square teeth from shearing off of the belt when it aged.
ineyeseekay@reddit
No difference on timing gear? Just thinking if it caused a slightly tighter fit, the rounded teeth might have slipped timing
yossarian19@reddit
the timing gear is definitely cut different for a rounded vs a square tooth.
spitestang@reddit
Them sending you the wrong part doesn't change the fact that you didn't verify before installing.
Hope this helps.
HSprof@reddit
This is my kind of comment thread.. at least we all understand whos to blame 🤣
I wouldnt do timing with anything other than oem parts
SoneiOTree@reddit (OP)
Yea, you're not finding an OEM timing belt from Nissan for an 88 300ZX. OEM parts like the t-belt, water pump, or t-belt tensioner. For Z32, yes. Z31, no.
HSprof@reddit
You definitely can. I have an 89 gti that I was able to find OEM parts for timing through a local importer. Theyre not 'genuine vw' they are made by the original european manufacturer, similar things exist for jdm which is far more popular
terribledirty@reddit
"Hope this help", can we ban this sour ass term from the internet? I'm so sick of you dorks, say it with your chest
Then-Pay-9688@reddit
Gulag for "I hope this helps." No need to be a cunt to someone asking for real help.
spitestang@reddit
He's not asking for help. No where in the post does he ask for help. He's "sharing his misfortune" aka bitching and blaming a vendor for his fuck up.
dextervw@reddit
2 full rotations with a wrench first, recheck marks are lined up then try a start. Usually catches any issues
SoneiOTree@reddit (OP)
Did and done prior to reassembly.
Zaxthran@reddit
Sorry this happened to you. There may still be hope. I don't know the VG33 but I'm pretty sure the VG30 is non-interference.
_ASHKINGKILLER_@reddit
VG33 is classified as an interference engine but unless the belt snaps at like 3k+ rpm’s then nothing will touch. I’ve got on in my 99 pathfinder with 380k and it’s still trucking along. Very stout engines. One guy in the PF group on facebook has bought 2 PF and one xterra with broken timing belts. He just put a new one on they are good as new lol
SoneiOTree@reddit (OP)
Agreed! My first VG30 had 265,000 miles and ran on only 2 cylinders with proper compression. They're not super interference, but interference enough to bend valves which I think is the case due to my floating rocker arms. Thankfully, I have some spare valves to throw in as long as the valve guides aren't also damaged.
Dangerous-Sock-3688@reddit
Time for a junkyard LS boiiii
SoneiOTree@reddit (OP)
I have some spare cylinder heads and valves from a previous 300ZX thankfully. As long as the pistons don't show damage and the valve guides are good, I'm replacing the valves and doing a valve job.
turbo_charged@reddit
I can’t argue with the floating rockers you found, but I’m not sure if a different timing belt tooth profile is enough to kill an engine. I imagine it would be noisy and probably slow to rev.
Did the timing belt jump time? Did you have a chance to check before you pulled it apart?
SoneiOTree@reddit (OP)
Yep! Jumped time. The belt also appeared that it wasn't seating comfortably and fully on the teeth after getting it started a few times. I had the belt tensioner as "loose" as it would go and it still felt too tight in my opinion. Another red flag I should have noticed...
2.5 years ago, I taught myself how to do engine work on one of these VG30s by doing a full rebuild at 265,000 miles. That car has had 6 new owners now and it's still kicking. After 10+ other project cars, I'm shocked I had the patience and willpower to do that after realizing how difficult they can be by working on this nightmare of a Z31.
imnota_@reddit
How was the tension after it jumped ?
Might've gotten loose after a few spins.
ZeGermanHam@reddit
I'm thinking the same way. If the belt was same exact length and same tooth count, I don't see it being the cause of OP's issue.
8N-QTTRO@reddit
According to a quick internet search, the belts are not the same length. The VG30 has 133 teeth, while the VG33 only has 130. After a few rotations, I'd imagine this would cause everything to become misaligned.
SoneiOTree@reddit (OP)
I'm seeing otherwise based off of my research.
8N-QTTRO@reddit
Actually, yeah. Looking at more part numbers, I'm seeing a Gates belt that's cross-listed as both VG30 and VG33 compatible. Which is equally as strange, since it implies the tooth shape doesn't actually matter.
patlaska@reddit
Looks like later VG30s had the round tooth belt, so that would make sense
ZeGermanHam@reddit
That would do it then. Gotta make what's going in is the same as what came out.
SoneiOTree@reddit (OP)
I did indeed rotate the engine by hand for several full rotations before complete reassembly. I felt 0 issues with it before full reassembly. I did everything by the books (Hayne's and FSM). This is my third T belt I've done on these engines and only time I have ever experienced something like this.
I know the timing belt tooth count like the back of my hand by now. 40 teeth between passenger/driver side cam, 43 teeth between driver side cam and crank sprocket.
ingannilo@reddit
If you rotated by hand and it was smooth and happy, and you verified TDC/cam orientation, and you counted teeth then the only possibilities are:
Damage prior to belt change
Or
Belt slipped/jumped after you turned it over by hand but before or during your startup.
The latter sounds very unlikely, especially if it was overly tight. The former... Well you'd know better than me.
Ambivadox@reddit
They're not that hard IF you take your time and do things right. Skipping basic steps like "make sure you're installing the right parts" is a recipe for disaster on any engine.
Troutsicle@reddit
Round tooth belts are not compatible with square tooth cam and crank gear profiles. You found out the hard way.
How did you set tension?
That's another part of the process that catches a few people, the way Nissan describes doing it in the FSM is highly subjective. I always set the tension by measuring deflection between the cam gears.
Unfortunlately you bent valves, now you are removing the heads and potentially dealing with another weakness of the VG30 in the Z31, 6mm exhaust studs that like to snap.
Good Luck.
dhabs@reddit
Just want to say between cams is da weh for fixed cam but not on VVT
hydrogen18@reddit
Thus, an LS swap is the only logical choice for the next step here.
ArCanSawDave@reddit
I had a friend who bought an eBay special timing kit for his Legacy's EJ25. I TOLD HIM that the timing set is not a place to try to cheap out on an engine! Sure enough the belt snapped on his way to work about 6 months later. Ruined the new heads he just put on the engine. There are lots of junk parts out on the internet, make sure you're buying from a legitimate parts source to have the best chance at getting decent stuff.
ypoora1@reddit
Especially Subaru is sensitive to cheapo belts and especially tensioners... I make sure i get mine OEM from the stealership for that reason
transboyadvance@reddit
Aisin makes Subaru OE & even includes the OE Mitsuboshi belt. No reason to go dealer unless you buy from somewhere that might sell you a counterfeit Aisin.
Kdiman@reddit
Nope you screwed something up if the belt was the same size and tooth count the bent valves are on you. You assembled it out of time or didn't release the tensioner. Something but that is the mechanic not the parts.
transboyadvance@reddit
Tooth shape is equally as important, or the belt will skip. Checking parts prior to installation is crucial
BoneyardRendezvous@reddit
I'd bet the belt was not seated fully on one of the pulleys. Rotating fine by hand but as soon as it really gets spinning it fell into place. Explains the tight belt, rotating fine by hand, and later damage.
HSprof@reddit
Let me fix that PSA for you..
I didnt verify my online parts before installing them and wrecked my engine
yossarian19@reddit
They sent you the wrong belt. You wrecked your engine and now you know to check the tooth profile as well as the length. You also may have learned not to ignore or brush off warning signs like 'this shit fits really tight'.
Sucks but the engine damage is on you, not them.
Dusty_Jangles@reddit
Stuff like this? Don’t cheap out. It will only lead to headaches like happened. Second of all, always always spin the motor a couple of times before starting just to verify there are no weird noises. I have also learned this the hard way. I got really really quick at tearing down the top end of a 350ci. Like 20 minutes quick.
Sir_J15@reddit
You installed the wrong belt and wrecked your own engine. As soon as you noticed it wasn’t going on right you should have not used it. The difference in teeth design will let it sit different in the wrong gears effectively causing a different length belt. This caused the timing to be off and caused the engine damage. This is a perfect example of forcing the wrong part and it causing catastrophic damage.
Independent_Dirt_814@reddit
Cheap parts was your first issue. Critical engine ruining parts should ONLY be purchased from reputable sources, and then verified the correct part before installation. Assuming you get the right parts puts you at fault for this.
MachWun@reddit
The cam gears on this engine have multiple timing marks on each gear depending on which side of the engine the gear is installed on.
Shipthenuts@reddit
Before starting the engine you always rotate 720°
weaseltorpedo@reddit
After you installed the new belt, and you turned the engine over twice at the crankshaft, did all the timing marks still line up? What about the position of the tensioner, after turning it over twice? Did anything feel weird when turning it over?
You did turn it over and verify correct timing before you started it, right?
jaslr4@reddit
There is the cheap way and the right way
XmodAlloy@reddit
It sounds like you got off by a tooth somewhere when you put the new belt on, creating the rough idle condition. It also sounds like it continued to slip again, causing the valve to piston interference...
The difference in the teeth profiles might have done it. Timing belts can be finicky. Just the awful quality of Partsology's advertisements on YouTube has made me steer clear of them. I generally go rockauto or OEM only, and for engine components I try to go OEM. With how old the car is though, that's not really feasible...
Ambivadox@reddit
" Some replacement valves or help with any other damaged parts due to their warehouse mishap would be nice, but no luck so far... Probably won't be working with them again."
So you didn't check that they were the correct parts and you want them to replace the parts you damaged?
They're not liable for anything except getting you the right belt. You screwed up.
8N-QTTRO@reddit
Warehouse mistakes can happen with every single retailer. This sounds less like a warning against the shop, and more like a cautionary tale to check all of your parts and ensure, without a doubt, that they are actually what you ordered before putting them on, especially when they're something engine-critical like timing on an interference engine.
TheGreatDuv@reddit
Always go by part number and parts diagrams.
Pretty much all parts shops have the same policies regarding returns and you aren't going to get any different response from other companies. Sending out the wrong stuff is going to happen with every single retailer in existence.
Whether it is a wrong listing on the website or a lazy/tired warehouse worker misreading a label. The problem is easily rectified upon you receiving the part, looking at the number and suitable application and going "oh that's the wrong one, return/exchange please"
But what you're asking of them is to replace a bunch of extra parts, because of improper installation. It's their fault you received the wrong part. It's your fault it was installed and caused damage.
Just take it on the chin, and be more vigilant with numbers.
Alpha_Hellhound@reddit
If it was super tight, why would you continue to put it on? Especially after verifying that the tooth profile was different. Seems like in your hurry to get it going, you possibly caused your problem to become a big issue.
-CaptainFormula-@reddit
"I'm tired boss." - your VG30E
That sucks brother, really and truly. Honestly if I'd have seen the difference in the teeth I'd have shrugged it off as a minor manufacturer/design decision as well. But not now, after reading this.
I hope they do something to help make it right.
8N-QTTRO@reddit
I doubt it. Pretty much every parts retailer has a bunch of stuff on their website saying to verify fitment before installing parts, verify you received the right parts, they're not responsible for parts installed improperly, etc. to cover their ass.
Also, OP definitely should've verified the part number instead of just slapping it on there.
SoneiOTree@reddit (OP)
I talked to support for 20 minutes when my blood pressure was still high yesterday and decided not to be a Karen by asking for a manager. That changes today now that I've calmed down haha