diff --git a/plugins/inputs/logparser/grok/testdata/test-patterns b/plugins/inputs/logparser/grok/testdata/test-patterns
deleted file mode 100644
index ba995fbd1..000000000
--- a/plugins/inputs/logparser/grok/testdata/test-patterns
+++ /dev/null
@@ -1,14 +0,0 @@
-# Test A log line:
-#   [04/Jun/2016:12:41:45 +0100] 1.25 200 192.168.1.1 5.432µs 101
-DURATION %{NUMBER}[nuµm]?s
-RESPONSE_CODE %{NUMBER:response_code:tag}
-RESPONSE_TIME %{DURATION:response_time:duration}
-TEST_LOG_A \[%{HTTPDATE:timestamp:ts-httpd}\] %{NUMBER:myfloat:float} %{RESPONSE_CODE} %{IPORHOST:clientip} %{RESPONSE_TIME} %{NUMBER:myint:int}
-
-# Test B log line:
-#   [04/06/2016--12:41:45] 1.25 mystring dropme nomodifier
-TEST_TIMESTAMP %{MONTHDAY}/%{MONTHNUM}/%{YEAR}--%{TIME}
-TEST_LOG_B \[%{TEST_TIMESTAMP:timestamp:ts-"02/01/2006--15:04:05"}\] %{NUMBER:myfloat:float} %{WORD:mystring:string} %{WORD:dropme:drop} %{WORD:nomodifier}
-
-TEST_TIMESTAMP %{MONTHDAY}/%{MONTHNUM}/%{YEAR}--%{TIME}
-TEST_LOG_BAD \[%{TEST_TIMESTAMP:timestamp:ts-"02/01/2006--15:04:05"}\] %{NUMBER:myfloat:float} %{WORD:mystring:int} %{WORD:dropme:drop} %{WORD:nomodifier}
diff --git a/plugins/inputs/logparser/grok/testdata/test_a.log b/plugins/inputs/logparser/grok/testdata/test_a.log
deleted file mode 100644
index a44d72fdf..000000000
--- a/plugins/inputs/logparser/grok/testdata/test_a.log
+++ /dev/null
@@ -1 +0,0 @@
-[04/Jun/2016:12:41:45 +0100] 1.25 200 192.168.1.1 5.432µs 101
diff --git a/plugins/inputs/logparser/grok/testdata/test_b.log b/plugins/inputs/logparser/grok/testdata/test_b.log
deleted file mode 100644
index 49e2983e8..000000000
--- a/plugins/inputs/logparser/grok/testdata/test_b.log
+++ /dev/null
@@ -1 +0,0 @@
-[04/06/2016--12:41:45] 1.25 mystring dropme nomodifier
diff --git a/plugins/parsers/grok/parser_test.go b/plugins/parsers/grok/parser_test.go
index b5810dc64..fb9ad442f 100644
--- a/plugins/parsers/grok/parser_test.go
+++ b/plugins/parsers/grok/parser_test.go
@@ -904,58 +904,3 @@ func TestNewlineInPatterns(t *testing.T) {
 	require.NoError(t, err)
 	require.NotNil(t, m)
 }
-
-func TestSyslogTimestamp(t *testing.T) {
-	tests := []struct {
-		name     string
-		line     string
-		expected time.Time
-	}{
-		{
-			name:     "two digit day of month",
-			line:     "Sep 25 09:01:55 value=42",
-			expected: time.Date(2018, time.September, 25, 9, 1, 55, 0, time.UTC),
-		},
-		{
-			name:     "one digit day of month single space",
-			line:     "Sep 2 09:01:55 value=42",
-			expected: time.Date(2018, time.September, 2, 9, 1, 55, 0, time.UTC),
-		},
-		{
-			name:     "one digit day of month double space",
-			line:     "Sep  2 09:01:55 value=42",
-			expected: time.Date(2018, time.September, 2, 9, 1, 55, 0, time.UTC),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			p := &Parser{
-				Patterns: []string{`%{SYSLOGTIMESTAMP:timestamp:ts-syslog} value=%{NUMBER:value:int}`},
-				timeFunc: func() time.Time { return time.Date(2017, time.April, 1, 0, 0, 0, 0, time.UTC) },
-			}
-			require.NoError(t, p.Compile())
-			m, err := p.ParseLine(tt.line)
-			require.NoError(t, err)
-			require.NotNil(t, m)
-			require.Equal(t, tt.expected, m.Time())
-		})
-	}
-}
-
-func TestReplaceTimestampComma(t *testing.T) {
-
-	p := &Parser{
-		Patterns: []string{`%{TIMESTAMP_ISO8601:timestamp:ts-"2006-01-02 15:04:05.000"} successfulMatches=%{NUMBER:value:int}`},
-	}
-
-	require.NoError(t, p.Compile())
-	m, err := p.ParseLine("2018-02-21 13:10:34,555 successfulMatches=1")
-	require.NoError(t, err)
-	require.NotNil(t, m)
-
-	require.Equal(t, 2018, m.Time().Year())
-	require.Equal(t, 13, m.Time().Hour())
-	require.Equal(t, 34, m.Time().Second())
-	//Convert Nanosecond to milisecond for compare
-	require.Equal(t, 555, m.Time().Nanosecond()/1000000)
-}