The 3 Most Common Honda J35 3.5 V6 Engine Problems

The Honda 3.5 V6 was first introduced in 1998 and the engine remains in models to this day. There are numerous variants and updates to the engine throughout the years. However, all engines share the same basic 3.5L V6 SOHC design. The engine offers a solid all-around balance of performance, fuel economy, and reliability. Despite its good reliability, the J35 is still prone to some issues including the timing belt, variable cylinder management, and carbon build-up. In this article, I discuss these Honda J35 engine problems along with overall reliability.

Common Honda 3.5 V6 Engine Problems

A few of the most common issues with the Honda J35 engine include:

• Variable Cylinder Management (VCM)
• Timing belt
• Carbon build-up

We’ll discuss these problems in-depth in the rest of this article. However, we feel its important to add a few quick notes to add some clarity. We’re considering these among the most common problems. That doesn’t mean they’re common in the sense the issues affect a large percentage of Honda 3.5 V6 engines. Rather, when failures occur these are a few of the most common areas.

That said, the 3.5L V6 offers pretty good overall reliability. We are talking about Honda, after all, and many know them for building reliable, long-lasting cars and engines. We’ll circle back to discussing reliability at the end of the article. Anyways, let’s move onto discussing the above issues.

If you would rather consume this content via a video, check out our Honda J35 Common Problems & Reliability video below:

1) Variable Cylinder Management Issues

Well, we’ve mentioned there’s a lot to unpack with all the various J35 engines. There’s just as much to discuss when it comes to Honda 3.5 V6 problems with the variable cylinder management (VCM) system. When the engine is under low loads the VCM shuts down one cylinder bank (3 cylinders). It’s great technology in theory. When you don’t need all of the power then why not shut down 3 cylinders to improve emissions and fuel economy? Nothing seems bad about that.

However, there have been plenty of reports with various flaws and failures of the VCM system. One issue lies within the J35 VCM gaskets, which are known to develop oil leaks. The Honda 3.5 VCM unit is is right near the alternator, which is not good news if leaks develop. If caught soon enough it’s not a huge concern, but oil leaking on the alternator isn’t great news.

It appears there are also cases of excess oil consumption due to the VCM. There was even a class action lawsuit in 2013 regarding the issue with high oil consumption for 2008-2013 models. It did not include the early 2005-2007 J35A7 engine, but some report issues with those VCM systems too. In addition to oil consumption – engine mounts, torque converters, and spark plug problems seem to be caused by Variable Cylinder Management.

Looking at the newest Honda 3.5 V6 Earth Dreams engine (J35Y) the problems don’t seem as prevalent. However, some still look to aftermarket solutions or disable the system. We believe this problem is blown out of proportion to some extent on the internet. Regardless, it’s still a problem that 3.5L V6 owners should be aware of.

Honda J35 VCM Symptoms

Symptoms of VCM issues can vary quite a bit. There are numerous issues that may occur with the VCM system (or due to VCM), so there’s not always one straight answer. However, a few things to look out for include:

• High oil consumption
• Oil leaks
• Vibrations
• Poor operation

Oil consumption is one of the main concerns with the VCM system. Ensure you’re checking the oil occasionally, and don’t just rely on the computer to tell you if and when it’s low. If the VCM gaskets are leaking you’ll likely notice an oil leak or smell burning oil. Vibrations or other problems may indicate the J35 engine mounts are on their way out.

Poor overall operation is very general, but we listed it as a symptom for good reason. Again, there are many things that may indicate Variable Cylinder Management faults. Poor operation might be a sign that it’s time to look into the VCM system.

VCM Fix

The exact fix, of course, depends on the issue at hand. However, there are some aftermarket solutions like these products, like from VCM Tuner. We can’t speak to their effectiveness, and would recommend doing some further research and digging. Otherwise, some elect to disable to VCM all together.

Those who live with the OEM solution may not run into any problems at all. In fact, most won’t run into issues since we believe this issue is blown out of proportion to some extent.

2) Timing Belt Wear

With the VCM discussion out of the way we’ll try to move through the next topics a bit faster. Timing belts aren’t really a true reliability issue on the Honda 3.5 V6 engine. The maintenance interval is every 8 years or 100,000 miles, but be sure to double check the manual for each specific J35 engine. It doesn’t seem there are any major flaws or faults with the J35 timing belt.

However, it’s a very important maintenance item and occasional checks are a good idea. The 3.5L V6 is an interference engine. That means there is overlap in the area the valves and pistons travel. Interference engines are generally more powerful and efficient. Though, if the timing belt snaps or slips too much then the valves and pistons can collide. Not good news.

When this occurs it’s not unusual to bend some valves. Further damage to the Honda 3.5 V6 could occur, too. Either way, bent valves will not be a cheap repair bill. Point is – there is no true problem with the Honda J35 timing belt, but it is a standard maintenance part. Once you’re nearing 6-8 years and 75,000 to 100,000 miles be sure to inspect the belt. Even if all looks good you’ll likely want to stick with the recommended interval.

Timing Belt Symptoms

• Weird engine noises (ticking/slapping)
• Misfires
• Check engine light (MIL)
• Power loss

It can be tough to detect any symptoms before the timing belt gives out. That’s part of the reason we believe visual inspections are a good idea as the Honda 3.5 timing belt nears the end of its service life. However, in some cases you might hear odd engine sounds similar to ticking or chattering.

Misfires, power loss, and a MIL may indicate the belt has slipped some. At this point it’s an urgent repair as too much slipping may lead to the valves and pistons colliding.

J35 Timing Belt Replacement

Fortunately, timing belt replacement is a pretty inexpensive repair. Depending on the year and model of your Honda 3.5 V6 the timing belt and water pump kit runs about $125-250. Speaking of, the water pump is a great thing to replace along with the belt. Seized water pumps can also cause issues with the timing belt, so it’s good preventative maintenance.

The job isn’t too challenging for the DIY crowd making it a very cheap repair. Those going to a repair shop should expect a few hours of labor, so add in another $150-300 for labor costs.

3) Carbon Build-Up Problems

Here we are writing about carbon build-up yet again. To note – this is an issue that only affects newer J35Y Earth Dreams engines that use direct injection. Many modern engines have made the switch from port injection (PI) to direct injection (DI). The change is generally for the better. Direct injection offers significant performance, emissions, and fuel economy benefits. All good stuff – it almost sounds too good to be true, right?

Carbon build-up on intake valves is one drawback to direct injection engines, like the Honda 3.5 V6 J35Y. Engines produce some degree of oil blow-by. This oil makes its way back into the intake tract where it sticks to intake ports and valves. Traditional PI sprays fuel into the intake ports and wipes away any deposits. However, direct injection sprays fuel directly into the 3.5L V6 cylinders. There’s nothing to wipe away oil deposits on the intake valves.

Over time, this causes carbon build-up on the intake valves and ports. It’s rarely an urgent issue, but intake valve cleaning on DI engines is usually good maintenance. Excess carbon deposits can cause drivability and performance issues. This is a topic that isn’t covered too much with the Honda J35 engine, yet. Carbon build-up problems don’t usually show until the 80,000 to 120,000+ mile ballpark.

Carbon Build-Up Symptoms

• Power loss
• Misfires
• Rough idle
• Stuttering / hesitation

One of the biggest performance issues with carbon build-up is power loss. It can be pretty significant in some cases. This is because carbon deposits actually begin restricting air-flow into the cylinders. Although, power loss can be really hard to notice since it occurs over tens of thousands of miles. It’s not a sudden loss of power which makes it hard to detect.

Otherwise, misfires are a major symptom of excess carbon deposits on the J35 intake valves. Misfires can be caused by many other issues, so it can be tough to detect. It’s usually better to start with the basics like spark plugs. If the simple things don’t solve the misfires then carbon build-up may very well be to blame.

Honda 3.5 V6 Reliability

How reliable is the Honda 3.5 V6 engine? We believe the engine earns above average remarks for reliability. Aside from the VCM concerns there aren’t many major flaws with the J35 engine. Some do run into problems with camshafts, but that may often boil down to poor maintenance. Otherwise, we didn’t have too much to discuss. Timing belts are simply important maintenance items, and carbon build-up is one downside to an otherwise great technology in direct injection.

Of course, a lot of reliability comes down to maintenance and that applies to the Honda 3.5 V6 engine too. We always recommend sticking with good oils, changing fluids on time, and fixing problems when they occur. Some reliability comes down to luck of the draw, and we can’t control that.

Maintain the 3.5L J35 engine well and it will likely reward you with a solid, reliable experience. It’s not uncommon for the Honda 3.5 V6 to make it past 200,000 miles without any major reliability issues.

J35 Common Problems Summary

Honda released the J35 3.5L engine in 1998 and it remains in production to this day. Given it’s two plus decade run there are tons of different variants of the Honda 3.5 V6. They all share the same basic 3.5L SOHC V6 design, though. They’re also all good engines that provide a respectable balance of power, efficiency, and reliability.

A few concerns and issues with the Honda VCM system are known and even brought about a lawsuit back in 2013. Fortunately, there are aftermarket options and ways to completely delete the system for anyone truly concerned. There weren’t many other true problems or flaws we could find to discuss. Timing belts and carbon build-up are fair discussions, but we don’t really consider them issues.

All in all, the 3.5 V6 provides good reliability and that’s especially true with proper maintenance. Stay on top of the basics and most Honda J35 owners will likely enjoy their time with the engine.

Check out some of our additional content including the Greatest Honda Engines of All Time and this J30 Engine Guide.