T4 Caravelle Engine Noise: Valve Tick?

Hello everyone!

"Recently, I've noticed a rattling sound when accelerating. Because the weather has been nice, I sometimes drive with the window down, and that's when I noticed it. The walls of the houses along the roadside seem to reflect the sound quite well. It sounds like a single valve rattling, but it could also be an injector; I'm not sure."

If you listen closely, you can hear the same noise on other T4 vehicles as well. Since I live near the regional hospital, a lot of T4s pass by my house, and some of them sound the same, but not all of them.

Is there a common defect or something that frequently breaks on the 5-cylinder engine?
I simply can't imagine where that's coming from right now. There's nothing to hear when it's idling.

Could the noise from the hydraulic lifters be caused by the thin long-life oil?

Greetings to you all.

Peter.

Hello.
On 5-cylinder engines, the vacuum pumps for the power brake booster often make a rattling noise.
For troubleshooting: remove the pump (using 2 x 8mm nuts); remove the drive plunger.
Reinstall the pump, start the engine (do not drive!), no power steering.
If the noise stops, the pump is broken.
The pump is very expensive (approximately 300-450 euros).
I know people who have driven 100,000 km with a faulty fuel pump.
Best regards, Jussi.

Hello!

"It's not the vacuum pump; that's working fine. I've been carefully listening to the whole thing. This clattering is synchronized with the firing order of the fifth cylinder, at least audibly. Of course, I don't know which cylinder is currently in its power stroke. But it's that typical sound of a five-cylinder engine, accompanied by a ticking. However, you really have to accelerate for it to be clearly audible. Could it be a faulty hydraulic lifter?"

Greetings, Peter.

Mc_Givertechnik wrote:

Could there possibly be a defective hydraulic lifter?

Hi Peter,

Okay, here's the translation:

"Try this: Warm up the engine and then let it run at a minimum of 3000 rpm. Then, remove the valve cover and push down on the lifters (the relevant camshaft lobe should be facing upwards -> the engine will rotate). Use a wooden wedge to depress the lifters. The clearance should be no more than 0.1 mm. If one lifter has more clearance than the others, you can generally assume there is a defect."