✅ 1. Ask for the actual compression numbers

She needs the numbers for all six cylinders (Honda Pilot = V6).

A proper test should show something like:

Cylinder 1: 185 psi

Cylinder 2: 180 psi

Cylinder 3: 60 psi ← This would be the problem

Etc.

If he can’t give the numbers → he didn’t do the test
and is just guessing.

✅ 2. Ask if they did a LEAK-DOWN TEST

This is the most important test.

It tells where the pressure is escaping:

Air from intake = bad intake valve

Air from exhaust = bad exhaust valve

Air from oil fill = worn rings

Air from coolant bubbles = head gasket

A compression test alone never proves the engine needs a rebuild.

A leak-down test reveals the true cause.

✅ 3. Many single-cylinder low PSI issues are FIXABLE without a rebuild

Here are common causes for ONE cylinder being low that do NOT require an engine rebuild:

✔️ Sticky or burnt valve

Often under $500–$1500 depending on shop.

✔️ Carbon buildup (very common on Honda V6)

Can often be fixed with:

top-end cleaning

intake valve cleaning

chemical treatments

✔️ Bad head gasket at that cylinder

Can be repaired without touching the bottom end.

✔️ Injector or ignition issue mimicking low compression

Sometimes a misfire gets misdiagnosed.

✔️ Worn rings in ONE cylinder (rare on Honda V6)

Even this does not always require a full rebuild — may just need a top-end refresh.

❗ When a rebuild might be needed

A rebuild is possible if:

Compression is extremely low (0–30 psi)

Leak-down test shows badly worn rings

Multiple cylinders are low

There is metal in the oil

Oil consumption is extreme

Engine overheated severely

But shops jumping straight to rebuild without doing a leak-down test is a red flag.

🚨 Ask this exact question

She should say to the mechanic:

“Can you send me the full compression test results and the leak-down test results?
Before doing a rebuild, I need to know the exact pressures and what the tests showed is causing the loss.”

If he avoids providing the numbers → he’s guessing or exaggerating.

🔧 Want me to help you evaluate her situation?

If you can get:

The compression numbers for all cylinders

Any leak-down percentages

Whether the engine is burning oil

Mileage of the Pilot

Any check engine codes

I can tell you within seconds whether a rebuild is reasonable or if she’s getting hustled.

Happy to write her a message to text the mechanic too.

You said:
so what exact tests should she ask for and can u give me parameters for pass or fail
ChatGPT said:

Here is the exact, no-bullshit list of tests she should request AND the pass/fail parameters for a Honda Pilot engine.
This is EXACTLY how to protect her from being upsold into a rebuild she may not need.

✅ THE 3 TESTS SHE MUST ASK FOR

These are industry-standard and every honest mechanic will agree to them.

1️⃣ Compression Test (already mentioned — but get numbers!)
What it measures:

How much pressure each cylinder can hold during cranking.

Honda Pilot V6 — PASS VALUES:

Normal range: 160–200 psi (varies slightly by year, but this is correct for all 3.5L V6s)

Cylinders should be within 10% of each other

FAIL VALUES (requires more investigation):

Any cylinder below 120 psi

Any cylinder more than 15% lower than the others

Zero compression (0–30 psi) → severe problem

BUT a compression test alone NEVER proves a rebuild is needed.
It only tells you which cylinder is struggling.

2️⃣ Leak-Down Test (MOST important test)

If a shop recommends a rebuild without performing this, walk away.

What it measures:

Where the compression is escaping — tells you the exact problem.

PASS VALUES:

0–10% leak → good

10–20% leak → acceptable, engine still healthy

FAIL VALUES (meaning something needs repair):

20–30% leak → noticeable problem

30–50% leak → serious issue

Above 50% → major failure in that cylinder

Where the air escapes = the diagnosis

Air from intake manifold → bad intake valve

Air from tailpipe → bad exhaust valve

Air from oil filler → piston rings

Bubbles in radiator → head gasket leak or warped head

This test determines whether she needs:

A small repair

A top-end repair

Or a full rebuild

Many times it’s something minor.

3️⃣ Oil Pressure Test
What it measures:

Whether the bottom end (bearings, pump) is healthy.

PASS VALUES (Honda Pilot):

10 psi per 1,000 RPM is the rule of thumb

Hot idle: ≥ 15–20 psi

At 3,000 RPM: ≥ 45–60 psi

FAIL VALUES:

Hot idle below 10 psi → worn bearings or pump

Erratic pressure → clogged pickup or pump issue

Pressure dropping when revving → major internal wear

If oil pressure is good →
The bottom end is healthy → No rebuild needed.

🎯 Optional but Helpful Tests

These aren’t required but strengthen the case:

4️⃣ Borescope Inspection

Camera inserted into the spark plug hole.

Pass:

Cylinder walls smooth

No scoring

Valves intact

Normal carbon

Fail:

Deep vertical scoring → ring damage

Broken valve/head damage

Coolant residue (head gasket)

5️⃣ Oil Analysis / Check for Metal

They drain the oil and inspect for metallic glitter.

Pass:

No metal

Normal dark oil

Fail:

Silver/chrome flakes → bearings failing

Copper/bronze → rod bearing damage

Frothy/milky → coolant contamination