The 3 Most Common Ford 3.5L Ti-VCT V6 (Cyclone & Duratec) Engine Problems

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If you’re a Duratec enthusiast, the V6 3.5L Ti-VCT engine might take your fancy due to its optimal performance, high reliability and durability, low gas consumption, and incredible anti-wear parts. Yet, there are issues you should be on the lookout for if your Ford car is built with this engine.

Typically, the three common Ford 3.5L Ti-VCT V6 engine problems:

  1. Damaged Cam Phasers
  2. Coolant-Oil Dilution
  3. Malfunctioning Water Pump

You may also notice a few other engine-related issues that need urgent attention. Don’t hesitate or postpone replacing or fixing them. The longer the problem lingers, the more risk your engine is exposed to.

Let us take a look at these problems one after another.

What Are The Most Common Ford 3.5L Ti-VCT V6 (Cyclone & Duratec) Engine Issues?

1. Damaged Cam Phasers

Here’s our icebreaker: more than 35% of your car engine problem is due to damaged cam phasers. In a car engine, the cam phaser rests on the back of the intake and exhaust chainwheels and fastened to the camshaft with the timing chain.

Controlled by a computer-powered servo, the cam phaser is essentially integrated into the engine to regulate the position of the camshaft proportionate to the pistons and crankshaft attached to the idling engine. The combustion engine houses the camshaft.

Primarily, the correct adjustment of the opening and closing of intake and exhaust valves are essential functions of the camshaft. Don’t forget, the valves are positioned under the camshaft.

Throttle response and drivability of your car rely on the functionality of the cam phasers because they improve the valve timing at a low revolution per minute (rpm). Once the rpm is low when the engine is running, NOX emission becomes low and fuel consumption is reduced significantly.

Once the cam phasers get bad due to torque-actuated reasons, the Variable Control Timing (VCT) solenoids won’t function optimally. The consequence is a failure in the engine’s performance, leading to a lack of control of the phaser by the engine control unit (ECU).

The attendant effect is the noise that comes from the phaser unit which is in turn primarily caused by the engine valve timing that’s not retarded fore or aft.

What Causes Cam Phasers To Damage?

There is a wide range of reasons your engine’s cam phasers can go bad. Generally, a cam phaser problem can be hydraulic, mechanical, or electrical. It is hydraulic if there is the low or poor oil viscosity, low oil pressure, or lack of oil flow.

Mechanical problems can come in the form of loose timing chains or stuck vanes. On the other hand, camp phasers issues due to electrical fault can be as a result of failed camshaft timing sensors or damaged solenoids. There are also noticeable wiring issues.

Here are a few of the specific causes of failed cam phasers:

  • Low oil pressure.
  • Poor oil viscosity.
  • Loss of engine power.
  • Gas gunk.
  • Faulty electrical unit.
  • Issue with gear.

Symptoms Of Faulty Cam Phaser

The 3.5L Ti-VCT V6 (Cyclone & Duratec) engine problems related to damaged cam phasers often show symptoms of earlier before issues deteriorate.

Here are signs that may tell if your cam phasers are faulty.

  • Engine Makes Knocking Noise: One of the earliest signs to show that your cam phaser has been damaged is a clicking noise that comes from the engine. The first suspect is the low oil pressure.
  • Check Engine Light Comes On: The check engine light will illuminate after the cam phasers have collapsed. The light serves as a code sent from the ECU which automatically defends the engine from running beyond the normal rpm.
  • Poor Engine Performance: Poor engine performance is a natural symptom that accompanies all major engine issues, including faulty cam phasers. You’ll notice engine misfiring and other engine-related issues.
  • Power Loss: If your cam phasers are damaged, you’ll notice a loss of power. Typically, the mid-range engine’s revolution per minute is at 4000, but may not pass 40 rpm. At this point, acceleration will reduce significantly.

How To Fix Damaged Cam Phasers

Prevention is the best maintenance. But maintenance is also a part of using the car. Either way, you’ll need to pay attention to the cam phaser issue in your car engine.

Here are steps to DIY diagnosis and fixing of damaged cam phasers:

Step 1: Diagnose The Problem

Using the scan tool, check which of the following issues arises:

  • Wiring or electrical breach.
  • Hydraulic passage problem with the filter screens mounted on the oil control solenoids.
  • Low engine oil viscosity and pressure.
  • Check for relevant scan codes.
Step 2: Fix The Bad Cam Phaser
  • Unplug all electrical components, including battery terminals, wiring plugs.
  • With compressed air, unbolt all bolts on the power steering reservoir and valve cover, dipstick tube.
  • Remove the air intake hose, the valve-cover positive crankcase ventilation hose, power train control module, and mounting bracket.
  • Disengage the cam timing solenoid and the ignition coil packs.
  • In between the two halves of the timing chain, insert the wedge tool.
  • With your dowel pin, label the position of the cam phaser relative to the camshaft and the timing chain.
  • Relax the cam phaser bolts using a bar breaker and the vice grips.
  • Disengage the cam phaser from the camshaft.
  • Install the new cam phaser using the dowel pin. Make sure you fasten the cam phasers bolts that you freshly set up to a 30fts/lbs-torque.

2. Coolant-Oil Dilution

The 3.5L Ti-VCT V6 engine problems can also result from the dilution of antifreeze and oil. Generally, oil dilution is a consequence of a wide range of underlying problems.

The primary cause of oil dilution is a failed water pump, and we shall talk about this shortly. Oil dilution in simple terms refers to the mixture of the engine oil with the coolant.

The position of the water pump makes it vulnerable to severe damage that may result in the coolant diluting with the oil. The good thing is that the water pump often leaks through the weep hole which makes the oil-antifreeze mixture a rare occurrence.

Typically, the issue starts with the interior bearings of the engine water pump. Then, the water pump may start to make a serious clunking noise that emanates from the pump itself and then all through different parts of the engine.

What Causes Oil In The Coolant System?

Oil-coolant dilution can be caused by a couple of things, some of which you may not have hitherto paid closer attention to:

  1. Cylinder Head Cracks.
  2. Cracked Oil Cooler.
  3. Faulty Head Gasket.
  4. Cracked Engine Block.

Symptoms Of Coolant-Oil Mixture

A mixture of antifreeze and oil indicates a few symptoms that you should be on the lookout for. They include:

  1. Overheating: Obviously, overheating is one of the clear signs when oil mixes with the coolant. You will see the temperature gauge rises on the dashboard.
  2. Rattling Engine Noise: Although there is a range of causes for engine rattling, its oil-coolant mixture is a major source. You’ll hear the engine make a terrible rattling noise during idle or acceleration. It can also occur when the engine oil is low.
  3. Milky-Looking Oil: The milky-looking oil is a clear sign that something is not right with the engine. The tan-colored oil often collects either in the oil fill seal or on the dipstick.

How To Fix Antifreeze-Oil Dilution

Whether it is the milky-looking oil, rattling water pump sound, or overheating in your 3.5L Ti-VCT V6 engine, you can get rid of them without breaking the bank. However, if the engine block gets cracked or allows other issues to degenerate, you may have to pay through your nose.

Here is a step-by-step guide on how to flush oil out of your coolant system:

Step 1: Inspect The Car For An Antifreeze Leak

Remove the coolant cap and, with the pressure tool, exert some pressure on the coolant system. If the pressure tool loses pressure, you’ll notice that the antifreeze leaks into the oil pan. As a precaution, the engine should be turned off for at least two and a half hours before the check takes place.

Don’t forget, the leak can be internal or external. If you can’t find any antifreeze under the car, then the leak is internal. From there you’ll need to disengage the oil cooler. Any crack in the gasket heads should immediately inform you that the coolant system is leaking.

However, if you still can’t find any crack, then you need an experienced mechanic to handle further checks.

Step 2: Fix Or Replace Damaged System

The outcome of the checks will determine whether you’ll need a complete replacement or repair of the damaged parts. If the oil-coolant mixture has stayed for long, it may result in the replacement of the engine.

However, if you noticed the mixture in good time, do the following immediately:

  1. Allow the engine to rest for about an hour. During this period, the antifreeze will not mix with the oil, keeping the former from the oil filter and while settling in the base of the sump.
  2. Remove the sump plug.
  3. Drain out the coolant until only engine oil starts to come out.
  4. Replace the sump plug.
  5. Top the oil to level or do a complete oil change.
  6. Make sure you change the oil filter as well.

3. Malfunctioning Water Pump

The last of the commonest 3.5L Ti-VCT V6 (Cyclone & Duratec) engine issue is the water pump failure. The pump helps to circulate coolant around the engine to dissipate temperature rise.

By design, the water pump of the 3.5 V6 Ti-VCT V6 engine is mounted beneath the timing seal. The pump is driven by the timing chain. Such design makes repair of the water pump a lot difficult; it also leaves the water pump at the risk of leaking.

Leaking can fail coolant flow, causing overheating and potential damage to the car engine.

Causes Of Water Pump Failure

  • Improper sealant or gasket.
  • Dry water pump rotation.
  • Use of wrong antifreeze.
  • Improper installation of drive belts.

Symptoms Of Faulty Water Pump

  • Overheating: Once the water pump fails, coolant may stop flowing and you’ll notice engine overheating by checking the temperature gauge on your dashboard.
  • Visible Coolant Leak: With the water pump damage, the engine antifreeze will start to leak, causing a reduction in the engine performance.
  • Oil-Coolant Dilution: There’s also a chance that the oil will mix with the coolant if the water pump fails. It is dangerous to allow the mixture to linger on.
  • Weep Hole Leakage: Another sign you might notice once there’s a failed water pump is the inability of the coolant to get to the bearing assembly. This is due to the contaminated coolant.

How To Fix Water Pump Failure

Once the water pump bearings unit starts to fail, you’ll need replacement. Don’t forget, replacement is a lot costlier than fixing. Doing a DIY method might be a lot difficult (not impossible) given the location of the water pump of a typical 3.6L Ti-VCT V6 engine.

But you’ll need some patience and skill. Hiring the services of a certified mechanic might be the best thing to do. You may need to budget something in the region of $1000-$1500 to fix or replace your 3.6L Ti-VCT V6 engine water pump.

With serious symptoms and problems, resolving a failed water pump requires buying a new water pump, for optimal engine performance. However, you’ll have to flush the cooling system thoroughly before you install the new pump.

For mild symptoms, like leakage from the mounting surface, you may only need to inspect the failing water pump and reinstall it. Overall, make use of the recommended coolant.


1. How Much Will I Need To Replace My 3.5L Ti-VCT V6 Engine Cam Phasers?

Generally, the cost of fixing your engine cam phaser depends on the extent of the damage and the type of cam phaser your engine runs on. A 3.5L Ti-VCT cam phaser costs up to $150.

Meanwhile, the cost of labor and buying other parts depend on the service you hire and the quality of the parts. In total, you should ready up to $750. But do not settle for cheap parts and labor.

2. Is The Oil-Coolant Mixture Harmful To The 3.5L V6 Engine?

The simple answer is yes, a mixture is dangerous to any engine. As regularly as possible, inspect your vehicle to avoid a dilution of the coolant and oil. These two substances serve different functions in the engine.

Oil is a thick substance that helps to lubricate the entire part of the engine for smooth drivability. The coolant is a water-like substance that cools off the engine, maximize flow, and resist heat rise.

Final Thoughts

The 3.5L Ti-VCT V6 engine problems highlighted here are partly due to design. It doesn’t, however, imply that they’re irresolvable.

In fact, being one of the best Ford engines on the market, the 3.5L Ti-VCT V6 (Cyclone & Duratec) engine comes with a great design. The 3.5L engine won’t perform optimally and may shut down if all issues are left unchecked.

I cannot overemphasize the importance of removing oil from the coolant system or replacing the water pump and cam phasers. If you force the engine to work, you may begin to notice a few explosions or sparks and the final collapse of the car.