Say Arrivederci to Your Cam Belt Cover!

FIAT owners have long had mixed feelings over the slew of coverings with which the Italian automaker adorned Aurelio Lampredi’s precious and innovative camshaft timing belts. While my position may not exactly make waves, I’d like to set out to treat you with (hopefully) the final word on the subject:

Kill it with fire.

Obviously, I don’t think anyone is a fool for keeping one on their car, but I’m here to change minds and improve lives, man. Roughly in order of importance, here are a myriad of reasons to liberate your overhead cam 1100, 1300, 1438, 1500, 1592, 1608, 1756, or 1995cc FIAT, Pininfarina, Bertone, or Lancia engine of its timing belt cover:

  1. It is unnecessary. That’s the truth. It might look like it protects your motor from debris, but your motor is actually safer without it. We have spoken with thousands of FIAT-family car owners, and have never once heard a credible tale of a properly maintained timing belt breaking on the street. I will elaborate at the close of the article, because this is such an important point, and I know some of us will need convincing.
  2. It hides your most important maintenance items. THIS is the single biggest reason FIAT overhead cam motors die: lack of timing belt and tensioner bearing maintenance. You can (at least partially) blame the timing belt cover for that phenomenon. As they say, “Out of sight, out of mind.” Many new owners don’t even realize they have a timing belt or tensioner because of the scourge that is the obtrusive timing cover.
  3. It makes your most important maintenance item harder to maintain. Anything you can do to lower the barrier to entry of timing belt maintenance is a good thing. Make it easier on yourself by leaving the cover off, and you will care for it more often. Seriously, removing the DOHC timing cover requires breaking the water jacket (opening the cooling system) of your motor — every single time you need to get behind the cover. And we all know how much fun it is to bleed the Lampredi cooling system…

It might look like it protects your motor from debris, but your motor is actually safer without it.

In the immortal words of Macaulay Culkin, “You guys give up, or are you thirsty for more?” Well, here’s even more reasons!

  1. It makes almost everything harder to get to. This is the flip side of point 3. Anything that makes general maintenance harder, without a significant upside, is a significant loss.
  2. It’s ugly. Seriously, why hide the beautiful workings of an advanced Italian engine? Especially if you have a nice set of anodized aluminum pulleys, there’s a lot to love about the front end of a 124 Spider or X1/9 powerplant.
  3. It’s one more thing to maintain. Following up on my last point, have you ever seen one of these that looked really nice after a few years? Sure, you can take it off, clean, and repaint it (both the plastic and aluminum covers pose certain challenges to proper paint adhesion), but what do you get in return for your effort? I’ll tell you what you get: hidden consumables, longer maintenance intervals, unnecessary bulk, and one more thing to worry about breaking if you have to work on it (again). Wouldn’t you much rather put that time into cleaning your carpet, or doing some task that really mattered (like your driveshaft flex joint)?
  4. It’s a freeloader. There’s a saying that dates back at least to the American Great Depression: “There ain’t no such thing as a free lunch.” Your timing belt cover wants to see the world at your expense. Sure, the heaviest covers still weigh less than five pounds (I haven’t checked one recently, because they’re all in the bin where they belong), but 100,000 or 200,000 miles is a long way to carry something that doesn’t benefit you in any quantifiable way.

What say we stop there and come back to the first — and most important — point: they are unnecessary. Imagine with me for a moment — the inside of your engine bay. Visualize the approach vectors to your timing belt, remembering that only a small area of the leading face of each pulley or idler poses a real threat. Let’s face it: the only way a rock is getting into a meaningful (read: dangerous) position along the route that your belt travels is if it becomes a “magic bullet.” My friend, I hate to tell you this, but if your belt breaks, it’s because there was a shooter on the grassy knoll. End of tragic metaphor.

Rocks and debris almost solely come up from the road surface when they bounce or get lifted by a tire. In order to hit them, you have to be traveling at a significant speed. If you consider that the maximum approach angle of a flying rock will be much less than 45 degrees, there’s really no way a rock is getting in there unless you have much bigger problems.

On a 124 or 131, the determined timing-belt-assassin would have — at the very least — to go through your radiator on it’s merry way to creating camshaft chaos. On an X1/9, well… it would probably have to go through the floor pan, your passenger’s hammies, the spare tire, and the firewall. So yeah, bigger problems.

So, without any more jibber-jabber on my part, I hope we can agree that timing belt covers are not the panacea that we’ve been sold. If anything, they may do much more harm than good, when you consider all the wonderful cars that went to scrapyards — and the FIAT reputation for “unreliability” — owing directly to American owners not realizing that they had a timing belt under that behemoth plastic eyesore.

Honestly, I think there’s a real possibility that the timing belt cover is the worst thing ever to happen to the fledgling Lampredi design, and one that we’ll do well to end in our time.

there’s a real possibility that the timing belt cover is the worst thing ever to happen to the fledgling Lampredi design

As always, thanks for reading,


10 thoughts on “Say Arrivederci to Your Cam Belt Cover!”

  1. I raced Kevlar belt Ducati motorcycles for years with no belt covers, no issues and belts ran cooler. Does the blog refer to the front and back side cover or just to the front?

    1. Hey Doug!
      As far as my gripes go, the front cover is the biggest offender. If you want to keep the rear for some reason, like timing marks, go for it. They’re mostly pretty ugly by themselves, so I tend to think it’s best to make/buy replacement timing markers if you have timing marks on any part of the covers.


  2. Aaron you’ve made some very valid points, I’m definitely putting it under consideration. However, you’ve mentioned “rocks” getting into the pulley cogs, what about coolant or even worst, oil? The coolant hose is sitting right next to the pulley, making the belt mechanism an easy target. Oil misting getting into the cogs could pose a threat of the belt slipping, would it not? While you’re considering those possibilities, would you recommend keeping the “lower” timing belt cover installed? Thanks much, your ideas are definitely worth considering.


    1. Hey Walter,
      I hear you. Here are a couple of thoughts to consider:

      First, these are toothed belts. We are probably both used to serpentine and V-belts, which have a tendency to slip as they age, or if they get very oily. They don’t need to maintain a fixed index to the crankshaft, so it’s no big deal. Toothed belts, however, are very good at maintaining their index, and I’ve only heard of a couple of credible cases of them jumping a tooth. Those were exclusively in high-RPM club racing situations, WELL outside original design parameters. That’s the kind of thing that just happens sometimes with racing. So there’s very little real evidence that this is a concern with high-performance motors, much less stock or street cars.

      Second, let’s theoretically consider where any oil mist is going to originate from. If you are losing a ton of compression past your piston rings (a.k.a. “blow-by”), the oil mist coming from the crankcase ventilator is still going straight into the intake or captured in a filter. Unless you are running an external (add-on) oil-cooler, you’re realistically likely to see oil leaks in four places: 1) Cam tower gaskets; 2) Camshaft seals; 3) Rear main crankshaft seal; and 4) Front crankshaft seal.

      The cam tower gaskets — both the rubber cover gaskets and the paper base gaskets — are notorious for leaks, due to the towers becoming pressurized under normal conditions. FIAT made the factory oil sends too large, and/or the oil returns too small. Without mods, they all leak eventually. The cover gaskets are easy to replace. Regardless, they tend to weep/ooze, not mist, because the mating surface has no moving parts. And surface tension keeps most of the ooze on the sides of the head and block. It’s a royal mess they’ll make over time, but not a major timing belt contaminant.

      Second, let’s take the camshaft and front crankshaft seal… Sure, they leak sometimes. Particularly on motors that don’t get enough driving. And they are in AWFULLY close proximity to your timing belt. Buuuuuuut… Think about this: keeping your timing belt cover actually makes it MORE likely that any dispersed oil particles collect on the timing belt and its pulleys/cog. Where else does that oil have to go? Your timing belt becomes a rather captive audience, so to speak, inside that cover. An oil leak is never ideal, but it’s much better to let it out into the open air as a mist than to let it churn around in the cam belt cover until it finds a porous surface like a rubber belt. Or condenses and collects into big drops, with even greater dangers.

      You mentioned coolant hoses, and there definitely should be some caution here in making sure your hoses fit properly and are not overly aged. I don’t really think this is an issue, but it’s up to the owner to double-check clearances. Many coolant hoses come with a little extra length supplied, so you can trim the hose down a tiny bit at one end if you think it may help you get extra clearance. Again, I don’t believe this is normally an issue, but double-check everything on an old car.

      Regarding the lower belt cover, it depends on a few factors. Trying to keep it brief, if you have one of many FIAT motors that use a window in the belt cover as the only factory source of crankshaft timing marks, you might consider keeping it for that reason. If you have the time and skill, you can transfer those marks to the block, or make yourself a new marker out of some sheet metal. Some motors have marks on the cover AND the block.

      Apart from that one useful factor, which only affects some motors (I’ll leave it to the reader to determine on their own motor), I think all of my points above stand as sufficient reasons to safely remove it, if you can.

      Again, this whole discussion is intended as advice, not dogma. So, if your timing cover is important to you, feel free to keep it. We don’t make a dime when someone takes off their timing belt cover. I just want to set the record straight that almost every reason I’ve ever heard for keeping them (except personal aesthetic preference) is either unsound from an engineering perspective, unsupported by experience, or both.

      And I’ve heard a lot of them.

      Thanks for taking the time to comment! Hope this was helpful. Let me know if you have any other thoughts!

    1. Hi Jeff!
      Assuming we’re talking crankshaft marks, some motors also have them cast or etched into the block. Otherwise, you’ll have to transfer them yourself, if you want to remove the cover. You can leave the rear part of the cover and scribe marks there, or make yourself a little timing pointer out of sheet metal. If those are beyond your time or ability, leaving the cover is alright. Just make sure to mark your calendar to check your belts!


  3. Well I don’t completely agree with you with this in mind. Once that timing belt stretches it Can run off the pulley and end up going through the radiator. Also if you are working on the motor while it’s running there is a possibility of getting clothing or something else caught it in causing a injury. So it isn’t just there to look pretty !

    1. Hey Melvin! Thanks for your comment, and it’s okay if we agree to disagree. I know it’s a contentious subject, and everyone is welcome to have an opinion. Hopefully, we can help each other toward even more well-informed opinions. I am curious, however: Have you ever seen really compelling evidence of this happening?

      I’d like to think through this idea of a timing belt damaging the radiator… FIAT themselves saw fit to go without belt guards on many of the factory cam pulleys. Importantly, the crank pulley prevents the belt from just walking off of the cam pulleys, unless there’s a REALLY major issue elsewhere (like the tensioner bearing running off-axis!). But the water neck comes out between the cam gears anyway (inside the belt’s path), and the radiator hoses run right in front of the belt. So even if it did manage to walk off, it lands on the water neck or the radiator hose.

      In order to actually damage the radiator, the belt would have to suddenly load up (elastically deform) and snap (suddenly releasing that stored energy), and the loaded end would have to swing in just the right direction in that final instant. The belt does not weigh much, and so has very little inertia left to act upon the radiator core, even if it did hit just right (missing the fan housing!). Still, the majority of the potential energy is perpendicular to the axis of the belt’s rotation (i.e.: emanating radially), so deflecting it toward the radiator would reduce what little inertia it had to begin with. Even modern front-wheel-drive automobiles, with their long serpentine belts aimed straight at the radiator, almost never spring leaks due a belt coming apart.

      Maybe you or your loved one has experienced radiator damage during a catastrophic belt failure (“Consult your doctor before taking Belterra, as it may interact with other medications”). I truly feel for you if that’s the case. But I think it’s unlikely. Either way, what you are describing is a one-in-a-million possibility that could only occur under a catastrophic failure condition — One that may well require a full engine rebuild. A belt cover will not save your motor if the belt fails, but it will make it more likely that the belt does fail — due to lack of maintenance!

      Bottom line: a radiator is much cheaper than an engine rebuild. Timing belt maintenance is cheaper still. Just my cost/benefit analysis of the absolute worst case scenario.

      Moving on, I actually think that your point on protecting the human element is fairly compelling, and one that I should address. No car is worth losing a finger over — or worse. Period.

      But, if you’ll grant this point, very few modern cars have a dedicated belt cover from the factory. Many have fan shrouds or plastic dress-up bits that make it a little more difficult to hurt yourself, but most manufacturers expect people to exercise caution, or bear their own consequences. Again, if you or someone you love has been injured in an auto maintenance accident, I feel for you. I hate that that is a possibility in this broken world.

      However, car guys and mechanics have always had to learn to respect the rotating mutilation-mill that is an internal combustion engine. Thankfully, the 124 hood opens in reverse, so it’s not possible to lean over the pulleys from the front (with the hood on). Still, we do everything we can without the engine running, and we protect ourselves when setting timing. With all that said, protecting the user is only one isolated reason in favor of the belt cover. It’s a good reason! It’s just not problematic enough to make me install a cover, or to stop me trying to convince others to do away with them.

      Whether you keep the cover or not, work safe! Because you work on cars at your own risk, and there are plenty of ways to hurt yourself.

      Thanks again,

      1. Thanks Aron, you certainly have valid points. I have been working on my own cars and trucks for many years. Yes I have had a friend get his shirt caught in a fan belt (not timing belt) . lucky he wasn’t hurt but his shirt did not survive. He never worked on a motor with his shirt unbuttoned again. I’m just one of those guys that says better safe than sorry.

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